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Configuration options

imgproxy is Twelve-Factor-App-ready and can be configured using ENV variables.

URL signature​

imgproxy allows URLs to be signed with a key and a salt. This feature is disabled by default, but is highly recommended to be enabled in production. To enable URL signature checking, define the key/salt pair:

  • IMGPROXY_KEY: hex-encoded key
  • IMGPROXY_SALT: hex-encoded salt
  • IMGPROXY_SIGNATURE_SIZE: number of bytes to use for signature before encoding to Base64. Default: 32

You can specify multiple key/salt pairs by dividing the keys and salts with a comma (,). imgproxy will check URL signatures with each pair. This is useful when you need to change key/salt pairs in your application while incurring zero downtime.

You can also specify file paths using the command line by referencing a separate file containing hex-coded keys and salts line by line:

imgproxy -keypath /path/to/file/with/key -saltpath /path/to/file/with/salt

If you need a random key/salt pair really fast, as an example, you can quickly generate one using the following snippet:

echo $(xxd -g 2 -l 64 -p /dev/random | tr -d '\n')
  • IMGPROXY_TRUSTED_SIGNATURES: a list of trusted signatures, comma divided. When set, imgproxy will trust the signatures from the list and won't check them even if IMGPROXY_KEY and IMGPROXY_SALT are set. Default: blank

Server​

  • IMGPROXY_BIND: the address and port or Unix socket to listen to. Default: :8080
  • IMGPROXY_NETWORK: the network to use. Known networks are tcp, tcp4, tcp6, unix, and unixpacket. Default: tcp
  • IMGPROXY_TIMEOUT: (deprecated alias: IMGPROXY_WRITE_TIMEOUT) the maximum duration (in seconds) for processing the response. Default: 10
  • IMGPROXY_READ_REQUEST_TIMEOUT: (deprecated alias: IMGPROXY_READ_TIMEOUT) the maximum duration (in seconds) for reading the entire incoming HTTP request, including the body. Default: 10
  • IMGPROXY_WRITE_RESPONSE_TIMEOUT: the maximum duration (in seconds) for writing the HTTP response body. Default: 10
  • IMGPROXY_KEEP_ALIVE_TIMEOUT: the maximum duration (in seconds) to wait for the next request before closing the connection. When set to 0, keep-alive is disabled. Default: 10
  • IMGPROXY_CLIENT_KEEP_ALIVE_TIMEOUT: the maximum duration (in seconds) to wait for the next request before closing the HTTP client connection. The HTTP client is used to download source images. When set to 0, keep-alive is disabled. Default: 90
  • IMGPROXY_DOWNLOAD_TIMEOUT: the maximum duration (in seconds) for downloading the source image. Default: 5
  • IMGPROXY_WORKERS: (alias: IMGPROXY_CONCURRENCY) the maximum number of images an imgproxy instance can process simultaneously without creating a queue. Default: the number of CPU cores multiplied by two
  • IMGPROXY_REQUESTS_QUEUE_SIZE: the maximum number of image requests that can be put in the queue. Requests that exceed this limit are rejected with 429 HTTP status. When set to 0, the requests queue is unlimited. Default: 0
  • IMGPROXY_MAX_CLIENTS: the maximum number of simultaneous active connections. When set to 0, connection limit is disabled. Default: 2048
  • IMGPROXY_TTL: a duration (in seconds) sent via the Cache-Control: max-age HTTP header. Default: 31536000 (1 year)
  • IMGPROXY_CACHE_CONTROL_PASSTHROUGH: when true and the source image response contains the Expires or Cache-Control headers, reuse those headers. Default: false
  • IMGPROXY_SET_CANONICAL_HEADER: when true and the source image has an http or https scheme, set a rel="canonical" HTTP header to the value of the source image URL. More details here. Default: false
  • IMGPROXY_SO_REUSEPORT: when true, enables SO_REUSEPORT socket option (currently only available on Linux and macOS);
  • IMGPROXY_PATH_PREFIX: the URL path prefix. Example: when set to /abc/def, the imgproxy URL will be /abc/def/%signature/%processing_options/%source_url. Default: blank
  • IMGPROXY_USER_AGENT: the User-Agent header that will be sent with the source image request. Default: imgproxy/%current_version
  • IMGPROXY_USE_ETAG: when set to true, enables using the ETag HTTP header for HTTP cache control. Default: false
  • IMGPROXY_ETAG_BUSTER: change this to change ETags for all the images. Default: blank
  • IMGPROXY_USE_LAST_MODIFIED: when set to true, enables using the Last-Modified HTTP header for HTTP cache control. Default: false
  • IMGPROXY_CUSTOM_REQUEST_HEADERS: pro list of custom headers that imgproxy will send while requesting the source image, divided by \; (can be redefined by IMGPROXY_CUSTOM_HEADERS_SEPARATOR). Example: X-MyHeader1=Lorem\;X-MyHeader2=Ipsum
  • IMGPROXY_CUSTOM_RESPONSE_HEADERS: pro a list of custom response headers, separated by \; (can be redefined by IMGPROXY_CUSTOM_HEADERS_SEPARATOR). Example: X-MyHeader1=Lorem\;X-MyHeader2=Ipsum
  • IMGPROXY_CUSTOM_HEADERS_SEPARATOR: pro a string that will be used as a custom header separator. Default: \;
  • IMGPROXY_REQUEST_HEADERS_PASSTHROUGH: pro a list of names of incoming request headers that should be passed through to the source image request.
  • IMGPROXY_RESPONSE_HEADERS_PASSTHROUGH: pro a list of names of source image response headers that should be passed through to the imgproxy response.
  • IMGPROXY_ENABLE_DEBUG_HEADERS: when set to true, imgproxy will add debug headers to the response. Default: false. The following headers will be added:
    • X-Origin-Content-Length: the size of the source image
    • X-Origin-Width: the width of the source image
    • X-Origin-Height: the height of the source image
    • X-Result-Width: the width of the resultant image
    • X-Result-Height: the height of the resultant image
  • IMGPROXY_SERVER_NAME: pro the Server header value. Default: imgproxy

Security​

imgproxy protects you from so-called image bombs. Here's how you can specify the maximum image resolution which you consider reasonable:

  • IMGPROXY_MAX_SRC_RESOLUTION: the maximum resolution of the source image, in megapixels. Images with larger actual size will be rejected. Default: 50

    warning

    When the source image is animated, imgproxy summarizes all its frames' resolutions while checking the source image resolution unless IMGPROXY_MAX_ANIMATION_FRAME_RESOLUTION is greater than zero.

  • IMGPROXY_MAX_SRC_FILE_SIZE: the maximum size of the source image, in bytes. Images with larger file size will be rejected. When set to 0, file size check is disabled. Default: 0

imgproxy can process animated images (GIF, WebP), but since this operation is pretty memory heavy, only one frame is processed by default. You can increase the maximum animation frames that can be processed number of with the following variable:

  • IMGPROXY_MAX_ANIMATION_FRAMES: the maximum number of animated image frames that may be processed. Default: 1
  • IMGPROXY_MAX_ANIMATION_FRAME_RESOLUTION: the maximum resolution of the animated source image frame, in megapixels. Images with larger actual frame size will be rejected. When set to 0, imgproxy will test the whole animated image resolution against IMGPROXY_MAX_SRC_RESOLUTION summarising all the frames' resolutions. Default: 0

To check if the source image is SVG, imgproxy reads some amount of bytes; by default it reads a maximum of 32KB. However, you can change this value using the following variable:

  • IMGPROXY_MAX_SVG_CHECK_BYTES: the maximum number of bytes imgproxy will read to recognize SVG files. If imgproxy is unable to recognize your SVG, try increasing this number. Default: 32768 (32KB)

Requests to some image sources may go through too many redirects or enter an infinite loop. You can limit the number of allowed redirects:

  • IMGPROXY_MAX_REDIRECTS: the max number of redirects imgproxy can follow while requesting the source image. When set to 0, no redirects are allowed. Default: 10

You can also specify a secret key to enable authorization with the HTTP Authorization header for use in production environments:

  • IMGPROXY_SECRET: the authorization token. If specified, the HTTP request should contain the Authorization: Bearer %secret% header.

If you don't want to reveal your source URLs, you can encrypt them with the AES-CBC algorithm:

  • IMGPROXY_SOURCE_URL_ENCRYPTION_KEY: hex-encoded key used for source URL encryption. Default: blank

    tip

    Read more about source URL encryption in the encrypting the source URL guide.

imgproxy does not send CORS headers by default. CORS will need to be allowed by using the following variable:

  • IMGPROXY_ALLOW_ORIGIN: when specified, enables CORS headers with the provided origin. CORS headers are disabled by default.

You can limit allowed source URLs with the following variable:

  • IMGPROXY_ALLOWED_SOURCES: a whitelist of source image URL prefixes divided by comma. Wildcards can be included with * to match all characters except /. When blank, imgproxy allows all source image URLs. Example: s3://,https://*.example.com/,local://. Default: blank

    warning

    Be careful when using this config to limit source URL hosts, and always add a trailing slash after the host.

    Bad: http://example.com

    Good: http://example.com/

    If the trailing slash is absent, http://example.com@baddomain.com would be a permissable URL, however, the request would be made to baddomain.com.

  • IMGPROXY_ALLOW_LOOPBACK_SOURCE_ADDRESSES: when true, allows connecting to loopback IP addresses (127.0.0.1-127.255.255.255 and IPv6 analogues) when requesting source images. Default: false

  • IMGPROXY_ALLOW_LINK_LOCAL_SOURCE_ADDRESSES: when true, allows connecting to link-local multicast and unicast IP addresses (224.0.0.1-224.0.0.255, 169.254.0.1-169.254.255.255, and IPv6 analogues) when requesting source images. Default: false

  • IMGPROXY_ALLOW_PRIVATE_SOURCE_ADDRESSES: when true, allows connecting to private IP addresses (10.0.0.0 - 10.255.255.255, 172.16.0.0 - 172.31.255.255, 192.168.0.0 - 192.168.255.255, and IPv6 analogues) when requesting source images. Default: true

  • IMGPROXY_PNG_UNLIMITED: when true, disables the limit on the number of PNG chunks. Default: false

    warning

    Disabling the limit on the number of PNG chunks can lead to memory exhaustion and DoS attacks.

  • IMGPROXY_SVG_UNLIMITED: when true, disables the limit on the SVG file size (10MB). Default: false

    warning

    Disabling the limit on the SVG file size can lead to memory exhaustion and DoS attacks.

  • IMGPROXY_SANITIZE_SVG: when true, imgproxy will remove scripts from SVG images to prevent XSS attacks. Defaut: true

When using imgproxy in a development environment, it can be useful to ignore SSL verification:

  • IMGPROXY_IGNORE_SSL_VERIFICATION: when true, disables SSL verification, so imgproxy can be used in a development environment with self-signed SSL certificates.

Also you may want imgproxy to respond with the same error message that it writes to the log:

  • IMGPROXY_DEVELOPMENT_ERRORS_MODE: when true, imgproxy will respond with detailed error messages. Not recommended for production because some errors may contain stack traces.

  • IMGPROXY_ALLOW_SECURITY_OPTIONS: when true, allows usage of security-related processing options such as max_src_resolution, max_src_file_size, max_animation_frames, and max_animation_frame_resolution. Default: false.

    warning

    IMGPROXY_ALLOW_SECURITY_OPTIONS allows bypassing your security restrictions. Don't set it to true unless you are completely sure that an attacker can't change your imgproxy URLs.

Cookies​

imgproxy can pass cookies in image requests. This can be activated with IMGPROXY_COOKIE_PASSTHROUGH. Unfortunately the Cookie header doesn't contain information about which URLs these cookies are applicable to, so imgproxy can only assume (or must be told).

When cookie forwarding is activated, by default, imgproxy assumes the scope of the cookies to be all URLs with the same hostname/port and request scheme as given by the headers X-Forwarded-Host, X-Forwarded-Port, X-Forwarded-Scheme or Host. To change that use IMGPROXY_COOKIE_BASE_URL.

  • IMGPROXY_COOKIE_PASSTHROUGH: when true, incoming cookies will be passed through the image request if they are applicable for the image URL. Default: false

  • IMGPROXY_COOKIE_BASE_URL: when set, assume that cookies have the scope of this URL for an incoming request (instead of using request headers). If the cookies are applicable to the image URL too, they will be passed along in the image request.

Compression​

  • IMGPROXY_QUALITY: the default quality of the resultant image, percentage. Default: 80
  • IMGPROXY_FORMAT_QUALITY: default quality of the resulting image per format, separated by commas. Example: jpeg=70,avif=40,webp=60. When a value for the resulting format is not set, the IMGPROXY_QUALITY value is used. Default: webp=79,avif=63,jxl=77

Advanced JPEG compression​

  • IMGPROXY_JPEG_PROGRESSIVE: when true, enables progressive JPEG compression. Default: false
  • IMGPROXY_JPEG_NO_SUBSAMPLE: pro when true, chrominance subsampling is disabled. This will improve quality at the cost of larger file size. Default: false
  • IMGPROXY_JPEG_TRELLIS_QUANT: pro when true, enables trellis quantisation for each 8x8 block. Reduces file size but increases compression time. Default: false
  • IMGPROXY_JPEG_OVERSHOOT_DERINGING: pro when true, enables overshooting of samples with extreme values. Overshooting may reduce ringing artifacts from compression, in particular in areas where black text appears on a white background. Default: false
  • IMGPROXY_JPEG_OPTIMIZE_SCANS: pro when true, splits the spectrum of DCT coefficients into separate scans. Reduces file size but increases compression time. Requires IMGPROXY_JPEG_PROGRESSIVE to be true. Default: false
  • IMGPROXY_JPEG_QUANT_TABLE: pro quantization table to use. Supported values are:
    • 0: Table from JPEG Annex K (default)
    • 1: Flat table
    • 2: Table tuned for MSSIM on Kodak image set
    • 3: Table from ImageMagick by N. Robidoux
    • 4: Table tuned for PSNR-HVS-M on Kodak image set
    • 5: Table from Relevance of Human Vision to JPEG-DCT Compression (1992)
    • 6: Table from DCTune Perceptual Optimization of Compressed Dental X-Rays (1997)
    • 7: Table from A Visual Detection Model for DCT Coefficient Quantization (1993)
    • 8: Table from An Improved Detection Model for DCT Coefficient Quantization (1993)

Advanced PNG compression​

  • IMGPROXY_PNG_INTERLACED: when true, enables interlaced PNG compression. Default: false
  • IMGPROXY_PNG_QUANTIZE: when true, enables PNG quantization. libvips should be built with Quantizr or libimagequant support. Default: false
  • IMGPROXY_PNG_QUANTIZATION_COLORS: maximum number of quantization palette entries. Should be between 2 and 256. Default: 256

Advanced WebP compression​

  • IMGPROXY_WEBP_COMPRESSION: pro the compression method to use. Supported values are lossy, near_lossless, and lossless. Default: lossy
  • IMGPROXY_WEBP_SMART_SUBSAMPLE: pro when true, enables smart subsampling. Smart subsampling increases the resulting file size and compression time but improves quality. Default: false

Advanced AVIF compression​

  • IMGPROXY_AVIF_SPEED: controls the CPU effort spent improving compression. The lowest speed is at 0 and the fastest is at 9. Default: 8

Advanced JPEG XL compression​

  • IMGPROXY_JXL_EFFORT: controls the CPU effort spent improving compression. The larger the value, the slower the encoding process but the better the compression. The value should be between 1 and 9. Default: 4

Autoquality​

imgproxy can calculate the quality of the resulting image based on selected metric. Read more in the Autoquality guide.

warning

Autoquality requires the image to be saved several times. Use it only when you prefer the resulting size and quality over the speed.

  • IMGPROXY_AUTOQUALITY_METHOD: pro the method of quality calculation. Default: none
  • IMGPROXY_AUTOQUALITY_TARGET: pro desired value of the autoquality method metric. Default: 0.02
  • IMGPROXY_AUTOQUALITY_MIN: pro minimal quality imgproxy can use. Default: 70
  • IMGPROXY_AUTOQUALITY_FORMAT_MIN: pro the minimal quality imgproxy can use per format, comma divided. Example: jpeg=70,avif=40,webp=60. When value for the resulting format is not set, IMGPROXY_AUTOQUALITY_MIN value is used. Default: avif=60
  • IMGPROXY_AUTOQUALITY_MAX: pro the maximum quality imgproxy can use. Default: 80
  • IMGPROXY_AUTOQUALITY_FORMAT_MAX: pro the maximum quality imgproxy can use per format, comma divided. Example: jpeg=70,avif=40,webp=60. When a value for the resulting format is not set, the IMGPROXY_AUTOQUALITY_MAX value is used. Default: avif=65
  • IMGPROXY_AUTOQUALITY_ALLOWED_ERROR: pro the allowed IMGPROXY_AUTOQUALITY_TARGET error. Applicable only to dssim and ml methods. Default: 0.001
  • IMGPROXY_AUTOQUALITY_MAX_RESOLUTION: pro when this value is greater then zero and the resultant resolution exceeds the value, autoquality won't be used. Default: 0
  • IMGPROXY_AUTOQUALITY_JPEG_NET: pro the path to the neural network for JPEG.
  • IMGPROXY_AUTOQUALITY_WEBP_NET: pro the path to the neural network for WebP.
  • IMGPROXY_AUTOQUALITY_AVIF_NET: pro the path to the neural network for AVIF.
  • IMGPROXY_AUTOQUALITY_JXL_NET: pro the path to the neural network for JPEG XL.

SVG processing​

  • IMGPROXY_SVG_FIX_UNSUPPORTED: when true, imgproxy will try to replace SVG features unsupported by librsvg to minimize SVG rendering error. This config only takes effect on SVG rasterization. Default: false
  • IMGPROXY_ALWAYS_RASTERIZE_SVG: when true, imgproxy will always rasterize SVG images unless SVG processing is not skipped. Default: false

AVIF/WebP/JPEG XL support detection​

imgproxy can use the Accept HTTP header to detect if the browser supports AVIF, WebP, or JPEG XL and use it as the default format. This feature is disabled by default and can be enabled by the following options:

  • IMGPROXY_AUTO_WEBP: (deprecated alias: IMGPROXY_ENABLE_WEBP_DETECTION) enables WebP support detection. When the file extension is omitted in the imgproxy URL and browser supports WebP, imgproxy will use it as the resulting format.
  • IMGPROXY_ENFORCE_WEBP: enables WebP support detection and enforces WebP usage. If the browser supports WebP, it will be used as resulting format even if another extension is specified in the imgproxy URL.
  • IMGPROXY_AUTO_AVIF: (deprecated alias: IMGPROXY_ENABLE_AVIF_DETECTION) enables AVIF support detection. When the file extension is omitted in the imgproxy URL and browser supports AVIF, imgproxy will use it as the resulting format.
  • IMGPROXY_ENFORCE_AVIF: enables AVIF support detection and enforces AVIF usage. If the browser supports AVIF, it will be used as resulting format even if another extension is specified in the imgproxy URL.
  • IMGPROXY_AUTO_JXL: enables JPEG XL support detection. When the file extension is omitted in the imgproxy URL and browser supports JPEG XL, imgproxy will use it as the resulting format.
  • IMGPROXY_ENFORCE_JXL: enables JPEG XL support detection and enforces JPEG XL usage. If the browser supports JPEG XL, it will be used as the resulting format even if another extension is specified in the imgproxy URL.
info

If multiple format detection/enforcement options are enabled, and the browser supports multiple of them, imgproxy will use the format with the highest priority. The priority is as follows (from the highest to the lowest): JPEG XL, AVIF, WebP

info

If both the source and the requested image formats support animation and AVIF detection/enforcement is enabled, AVIF won't be used as AVIF sequence is not supported yet.

info

If both the source and the requested image formats support animation and JPEG XL detection/enforcement is enabled, JPEG XL won't be used as animated JPEG XL is not widely supported by browsers yet.

tip

When AVIF/WebP/JPEG XL support detection is enabled, please take care to configure your CDN or caching proxy to take the Accept HTTP header into account while caching.

warning

Headers cannot be signed. This means that an attacker can bypass your CDN cache by changing the Accept HTTP headers. Keep this in mind when configuring your production caching setup.

Preferred formats​

When the resulting image format is not explicitly specified in the imgproxy URL via the extension or the format processing option, imgproxy will choose one of the preferred formats:

  • IMGPROXY_PREFERRED_FORMATS: a list of preferred formats, comma divided. Default: jpeg,png,gif

imgproxy is guided by the following rules when choosing the resulting format:

  1. If the preferred formats list contains the source image format, it will be used
  2. If the resulting image is animated, the resulting image format should support animations
  3. If the resulting image contains transparency, the resulting image format should support transparency
  4. imgproxy chooses the first preferred format that meets those requirements
  5. If none of the preferred formats meet the requirements, the first preferred format is used
info

When AVIF/WebP/JPEG XL support detection is enabled and the browser supports AVIF/WebP/JPEG XL, it may be used as the resultant format even if the preferred formats list doesn't contain it.

Skip processing​

You can configure imgproxy to skip processing of some formats:

  • IMGPROXY_SKIP_PROCESSING_FORMATS: a list of formats that imgproxy shouldn't process, comma divided.
info

Processing can only be skipped when the requested format is the same as the source format.

info

Video thumbnail processing can't be skipped.

Best format​

You can use the best value for the format option or the extension to make imgproxy pick the best format for the resultant image.

  • IMGPROXY_BEST_FORMAT_COMPLEXITY_THRESHOLD: pro the image complexity threshold. imgproxy will use a lossless or near-lossless encoding for images with low complexity. Default: 5.5
  • IMGPROXY_BEST_FORMAT_MAX_RESOLUTION: pro when greater than 0 and the image's resolution (in megapixels) is larger than the provided value, imgproxy won't try all the applicable formats and will just pick one that seems the best for the image
  • IMGPROXY_BEST_FORMAT_BY_DEFAULT: pro when true and the resulting image format is not specified explicitly, imgproxy will use the best format instead of the source image format
  • IMGPROXY_BEST_FORMAT_ALLOW_SKIPS: pro when true and the best format is used, imgproxy will skip processing of SVG and formats listed to skip processing

Check out the Best format guide to learn more.

Client Hints support​

imgproxy can use the Width and DPR HTTP headers to determine default width and DPR options using Client Hints. This feature is disabled by default and can be enabled by the following option:

  • IMGPROXY_ENABLE_CLIENT_HINTS: enables Client Hints support to determine default width and DPR options. Read more details here about Client Hints.
warning

Headers cannot be signed. This means that an attacker can bypass your CDN cache by changing the Width or DPR HTTP headers. Keep this in mind when configuring your production caching setup.

Video thumbnails​

imgproxy Pro can extract specific video frames to create thumbnails. This feature is disabled by default, but can be enabled with IMGPROXY_ENABLE_VIDEO_THUMBNAILS.

  • IMGPROXY_ENABLE_VIDEO_THUMBNAILS: pro when true, enables video thumbnail generation. Default: false
  • IMGPROXY_VIDEO_THUMBNAIL_SECOND: pro the timestamp of the frame (in seconds) that will be used for a thumbnail. Default: 1
  • IMGPROXY_VIDEO_THUMBNAIL_KEYFRAMES: pro when true, imgproxy will use the latest keyframe before IMGPROXY_VIDEO_THUMBNAIL_SECOND for video thumbnail generation. This makes video thumbnail generation faster yet the used frame timestamp will not be exactly equal to the requested one. Default: false
  • IMGPROXY_VIDEO_THUMBNAIL_TILE_AUTO_KEYFRAMES: pro when true and the step argument value of the video_thumbnail_tile processing option is greater than the interval between keyframes, imgproxy will use only keyframes. This allows to speed up video_thumbnail_tile for long steps between tiles yet keep it precise for short ones. Default: false
  • IMGPROXY_VIDEO_THUMBNAIL_PROBE_SIZE: pro the maximum amount of bytes used to determine the format. Lower values can decrease memory usage but can produce inaccurate data, or even lead to errors. Default: 5000000
  • IMGPROXY_VIDEO_THUMBNAIL_MAX_ANALYZE_DURATION: pro the maximum number of milliseconds used to get the stream info. Lower values can decrease memory usage but can produce inaccurate data, or even lead to errors. When set to 0, the heuristic is used. Default: 0
warning

Though using IMGPROXY_VIDEO_THUMBNAIL_PROBE_SIZE and IMGPROXY_VIDEO_THUMBNAIL_MAX_ANALYZE_DURATION can lower the memory footprint of video thumbnail generation, they should be used in production only when you know what you're doing.

Watermark​

  • IMGPROXY_WATERMARK_DATA: Base64-encoded image data. You can easily calculate it with base64 tmp/watermark.png | tr -d '\n'.
  • IMGPROXY_WATERMARK_PATH: the path to the locally stored image
  • IMGPROXY_WATERMARK_URL: the watermark image URL
  • IMGPROXY_WATERMARK_PREPROCESS_URL: pro when true, imgproxy will apply IMGPROXY_URL_REPLACEMENTS and IMGPROXY_BASE_URL to values of the watermark_url processing option.
  • IMGPROXY_WATERMARK_OPACITY: the watermark's base opacity
  • IMGPROXY_WATERMARKS_CACHE_SIZE: pro custom watermarks cache size. When set to 0, the watermark cache is disabled. 256 watermarks are cached by default.

Read more about watermarks in the Watermark guide.

Unsharp masking​

imgproxy Pro can apply unsharp masking to your images.

  • IMGPROXY_UNSHARP_MASKING_MODE: pro controls when unsharp masking should be applied. The following modes are supported:
    • auto: (default) apply unsharp masking only when an image is downscaled and the sharpen option has not been set.
    • none: unsharp masking is not applied.
    • always: always applies unsharp masking.
  • IMGPROXY_UNSHARP_MASKING_WEIGHT: pro a floating-point number that defines how neighboring pixels will affect the current pixel. The greater the value, the sharper the image. This value should be greater than zero. Default: 1
  • IMGPROXY_UNSHARP_MASKING_DIVIDER: pro a floating-point number that defines unsharp masking strength. The lesser the value, the sharper the image. This value be greater than zero. Default: 24

Smart crop​

  • IMGPROXY_SMART_CROP_ADVANCED: pro when true, enables usage of the advanced smart crop method. Advanced smart crop may take more time than regular one, yet it produces better results.
  • IMGPROXY_SMART_CROP_ADVANCED_MODE: pro the mode of the advanced smart crop method. Supported values are:
    • max_score_area: (default) in this mode, imgproxy builds a featres map and selects the area with the highest sum of feature scores.
    • center_of_mass: in this mode, imgproxy calculates the center of mass of the features map and selects the area around it.
  • IMGPROXY_SMART_CROP_FACE_DETECTION: pro when true, adds an additional fast face detection step to smart crop.

Object detection​

imgproxy can detect objects on the image and use them to perform smart cropping, to blur the detections, or to draw the detections.

  • IMGPROXY_OBJECT_DETECTION_CONFIG: pro the path to the neural network config in DarkNet format. Default: blank
  • IMGPROXY_OBJECT_DETECTION_WEIGHTS: pro the path to the neural network weights in DarkNet format. Default: blank
  • IMGPROXY_OBJECT_DETECTION_NET: pro a path to the neural network model in ONNX format. Default: blank
  • IMGPROXY_OBJECT_DETECTION_NET_TYPE: pro the type of the neural network model. Default: yolox
  • IMGPROXY_OBJECT_DETECTION_CLASSES: pro the path to the text file with the classes names, one per line. Default: blank
  • IMGPROXY_OBJECT_DETECTION_NET_SIZE: pro the size of the neural network input. The width and the heights of the inputs should be the same, so this config value should be a single number. Default: 416
  • IMGPROXY_OBJECT_DETECTION_CONFIDENCE_THRESHOLD: pro detections with confidences below this value will be discarded. Default: 0.2
  • IMGPROXY_OBJECT_DETECTION_NMS_THRESHOLD: pro non-max supression threshold. Don't change this if you don't know what you're doing. Default: 0.4
  • IMGPROXY_OBJECT_DETECTION_SWAP_RB: pro when set to true, imgproxy will swap the R and B channels in the input image. Some models are trained on BGR images and perform incorrectly with RGB inputs. This option allows you to fix this issue. Default: false
  • IMGPROXY_OBJECT_DETECTION_FALLBACK_TO_SMART_CROP: pro defines imgproxy's behavior when object-oriented crop gravity is used but no objects are detected. When set to true, imgproxy will fallback to smart crop. When set to false, imgproxy will fallback to the center gravity. Default: true
  • IMGPROXY_OBJECT_DETECTION_GRAVITY_MODE: pro defines how imgproxy should use object-oriented crop gravity. Supported values are:
    • max_score_area: (default) in this mode, imgproxy will select the area that covers the most detected objects, respecting their weights.
    • one_best: in this mode, imgproxy will focus on the object with the highest score based on its area, confidence, and class weight.
    • one_best_centermost: the same as one_best, but imgproxy will add the object's proximity to the image center to its score.

Read the Object Detection guide for more info.

Fallback image​

You can set up a fallback image that will be used in case imgproxy is unable to fetch the requested one. Use one of the following variables:

  • IMGPROXY_FALLBACK_IMAGE_DATA: Base64-encoded image data. You can easily calculate it with base64 tmp/fallback.png | tr -d '\n'.
  • IMGPROXY_FALLBACK_IMAGE_PATH: the path to the locally stored image
  • IMGPROXY_FALLBACK_IMAGE_URL: the fallback image URL
  • IMGPROXY_FALLBACK_IMAGE_PREPROCESS_URL: pro when true, imgproxy will apply IMGPROXY_URL_REPLACEMENTS and IMGPROXY_BASE_URL to values of the fallback_image_url processing option.
  • IMGPROXY_FALLBACK_IMAGE_HTTP_CODE: the HTTP code for the fallback image response. When set to zero, imgproxy will respond with the usual HTTP code. Default: 200
  • IMGPROXY_FALLBACK_IMAGE_TTL: a duration (in seconds) sent via the Cache-Control: max-age HTTP header when a fallback image was used. When blank or 0, the value from IMGPROXY_TTL is used.
  • IMGPROXY_FALLBACK_IMAGES_CACHE_SIZE: pro the size of custom fallback images cache. When set to 0, the fallback image cache is disabled. 256 fallback images are cached by default.

Presets​

Read more about imgproxy presets in the Presets guide.

There are two ways to define presets:

Using an environment variable​

  • IMGPROXY_PRESETS: a set of processing preset definitions, comma divided. Example: default=resizing_type:fill/enlarge:1,sharp=sharpen:0.7,blurry=blur:2. Default: blank
  • IMGPROXY_INFO_PRESETS: pro a set of info preset definitions, comma divided. Example: default=xmp:0/blurhash:4:3. Default: blank
  • IMGPROXY_PRESETS_SEPARATOR: a string that will be used as a presets' separator. Default: ,

Using a command line argument​

imgproxy -presets /path/to/file/with/presets -info-presets /path/to/file/with/info-presets

This file should contain preset definitions, one per line. Lines starting with # are treated as comments. Example:

default=resizing_type:fill/enlarge:1

# Sharpen the image to make it look better
sharp=sharpen:0.7

# Blur the image to hide details
blurry=blur:2

Using only presets​

imgproxy can be switched into "presets-only mode". In this mode, imgproxy accepts only preset option arguments as processing options. Example: http://imgproxy.example.com/unsafe/thumbnail:blurry:watermarked/plain/http://example.com/images/curiosity.jpg@png

  • IMGPROXY_ONLY_PRESETS: when true, enables presets-only mode. Default: false
  • IMGPROXY_INFO_ONLY_PRESETS: when true, enables presets-only mode for the info endpoint. Default: IMGPROXY_ONLY_PRESETS value

Image sources​

Local files​

imgproxy can serve your local images, but this feature is disabled by default. To enable it, specify your local filesystem root:

  • IMGPROXY_LOCAL_FILESYSTEM_ROOT: the root of the local filesystem. Keep this empty to disable local file serving.

Check out the Serving local files guide to learn more.

Amazon S3​

imgproxy can process files from Amazon S3 buckets, but this feature is disabled by default. To enable it, set IMGPROXY_USE_S3 to true:

  • IMGPROXY_USE_S3: when true, enables image fetching from Amazon S3 buckets. Default: false
  • IMGPROXY_S3_REGION: an S3 buckets region
  • IMGPROXY_S3_ENDPOINT: a custom S3 endpoint to being used by imgproxy
  • IMGPROXY_S3_ENDPOINT_USE_PATH_STYLE: controls how the S3 bucket endpoint is constructed. When true, the endpoint will be constructed using the path style (https://your-endpoint.com/%bucket). When false, the endpoint will be constructed using the virtual host style (https://%bucket.your-endpoint.com). Default: true
  • IMGPROXY_S3_MULTI_REGION: when true, allows using S3 buckets from different regions. Default: false
  • IMGPROXY_S3_USE_DECRYPTION_CLIENT: when true, enables client-side decryption. Default: false
  • IMGPROXY_S3_ASSUME_ROLE_ARN: a custom role to assume
  • IMGPROXY_S3_ASSUME_ROLE_EXTERNAL_ID: the external ID required to assume a custom role

Check out the Serving files from S3 guide to learn more.

Google Cloud Storage​

imgproxy can process files from Google Cloud Storage buckets, but this feature is disabled by default. To enable it, set the value of IMGPROXY_USE_GCS to true:

  • IMGPROXY_USE_GCS: when true, enables image fetching from Google Cloud Storage buckets. Default: false
  • IMGPROXY_GCS_KEY: the Google Cloud JSON key. When set, enables image fetching from Google Cloud Storage buckets. Default: blank
  • IMGPROXY_GCS_ENDPOINT: a custom Google Cloud Storage endpoint to being used by imgproxy

Check out the Serving files from Google Cloud Storage guide to learn more.

Azure Blob Storage​

imgproxy can process files from Azure Blob Storage containers, but this feature is disabled by default. To enable it, set IMGPROXY_USE_ABS to true:

  • IMGPROXY_USE_ABS: when true, enables image fetching from Azure Blob Storage containers. Default: false
  • IMGPROXY_ABS_NAME: the Azure account name. Default: blank
  • IMGPROXY_ABS_KEY: the Azure account key. Default: blank
  • IMGPROXY_ABS_ENDPOINT: the custom Azure Blob Storage endpoint to be used by imgproxy. Default: blank

Check out the Serving files from Azure Blob Storage guide to learn more.

OpenStack Object Storage ("Swift")​

imgproxy can process files from OpenStack Object Storage, but this feature is disabled by default. To enable it, set IMGPROXY_USE_SWIFT to true.

  • IMGPROXY_USE_SWIFT: when true, enables image fetching from OpenStack Swift Object Storage. Default: false
  • IMGPROXY_SWIFT_USERNAME: the username for Swift API access. Default: blank
  • IMGPROXY_SWIFT_API_KEY: the API key for Swift API access. Default: blank
  • IMGPROXY_SWIFT_AUTH_URL: the Swift Auth URL. Default: blank
  • IMGPROXY_SWIFT_AUTH_VERSION: the Swift auth version, set to 1, 2 or 3 or leave at 0 for autodetect.
  • IMGPROXY_SWIFT_TENANT: the tenant name (optional, v2 auth only). Default: blank
  • IMGPROXY_SWIFT_DOMAIN: the Swift domain name (optional, v3 auth only): Default: blank
  • IMGRPOXY_SWIFT_TIMEOUT_SECONDS: the data channel timeout in seconds. Default: 60
  • IMGRPOXY_SWIFT_CONNECT_TIMEOUT_SECONDS: the connect channel timeout in seconds. Default: 10

Check out the Serving files from OpenStack Object Storage guide to learn more.

Source image URLs​

  • IMGPROXY_BASE_URL: a base URL prefix that will be added to each source image URL. For example, if the base URL is http://example.com/images and /path/to/image.png is requested, imgproxy will download the source image from http://example.com/images/path/to/image.png. If the image URL already contains the prefix, it won't be added. Default: blank

  • IMGPROXY_URL_REPLACEMENTS: a list of pattern=replacement pairs, semicolon (;) divided. imgproxy will replace source URL prefixes matching the pattern with the corresponding replacement. Wildcards can be included in patterns with * to match all characters except /. ${N} in replacement strings will be replaced with wildcard values, where N is the number of the wildcard. Examples:

    • mys3://=s3://my_bucket/images/ will replace mys3://image01.jpg with s3://my_bucket/images/image01.jpg
    • mys3://*/=s3://my_bucket/${1}/images will replace mys3://items/image01.jpg with s3://my_bucket/items/images/image01.jpg
info

Replacements defined in IMGPROXY_URL_REPLACEMENTS are applied before IMGPROXY_BASE_URL is added.

Metrics​

New Relic​

imgproxy can send its metrics to New Relic. Specify your New Relic license key to activate this feature:

  • IMGPROXY_NEW_RELIC_KEY: the New Relic license key
  • IMGPROXY_NEW_RELIC_APP_NAME: a New Relic application name. Default: imgproxy
  • IMGPROXY_NEW_RELIC_LABELS: the list of New Relic labels, semicolon divided. Example: label1=value1;label2=value2. Default: blank

Check out the New Relic guide to learn more.

Prometheus​

imgproxy can collect its metrics for Prometheus. Specify a binding for Prometheus metrics server to activate this feature:

  • IMGPROXY_PROMETHEUS_BIND: Prometheus metrics server binding. Can't be the same as IMGPROXY_BIND. Default: blank
  • IMGPROXY_PROMETHEUS_NAMESPACE: Namespace (prefix) for imgproxy metrics. Default: blank

Check out the Prometheus guide to learn more.

Datadog​

imgproxy can send its metrics to Datadog:

  • IMGPROXY_DATADOG_ENABLE: when true, enables sending metrics to Datadog. Default: false
  • IMGPROXY_DATADOG_ENABLE_ADDITIONAL_METRICS: when true, enables sending the additional metrics to Datadog. Default: false
warning

Since the additional metrics are treated by Datadog as custom, Datadog can additionally bill you for their usage. Please, check out Datadog's Custom Metrics Billing page for additional details.

Check out the Datadog guide to learn more.

OpenTelemetry​

imgproxy can send request traces to an OpenTelemetry collector:

  • IMGPROXY_OPEN_TELEMETRY_ENABLE: when true, enables sending request traces to OpenTelemetry collector. Default: false
  • IMGPROXY_OPEN_TELEMETRY_ENABLE_METRICS: when true, imgproxy will send metrics over OpenTelemetry Metrics API. Default: false
  • IMGPROXY_OPEN_TELEMETRY_SERVER_CERT: OpenTelemetry collector TLS certificate, PEM-encoded (you can replace line breaks with \n). Default: blank
  • IMGPROXY_OPEN_TELEMETRY_CLIENT_CERT: OpenTelemetry client TLS certificate, PEM-encoded (you can replace line breaks with \n). Default: blank
  • IMGPROXY_OPEN_TELEMETRY_CLIENT_KEY: OpenTelemetry client TLS key, PEM-encoded (you can replace line breaks with \n). Default: blank
  • IMGPROXY_OPEN_TELEMETRY_TRACE_ID_GENERATOR: OpenTelemetry trace ID generator. Supported generators are xray and random. Default: xray

Check out the OpenTelemetry guide to learn more.

Amazon CloudWatch metrics​

imgproxy can send its metrics to Amazon CloudWatch. Specify a desired ServiceName dimesion value to activate this feature:

  • IMGPROXY_CLOUD_WATCH_SERVICE_NAME: the value of the ServiceName dimension which will be used in the metrics. Default: blank
  • IMGPROXY_CLOUD_WATCH_NAMESPACE: the CloudWatch namespace for the metrics
  • IMGPROXY_CLOUD_WATCH_REGION: the code of the AWS region to which the metrics should be sent

Check out the CloudWatch guide to learn more.

Error reporting​

imgproxy can report occurred errors to Bugsnag, Honeybadger and Sentry:

  • IMGPROXY_REPORT_DOWNLOADING_ERRORS: when true, imgproxy will report downloading errors. Default: true

Bugsnag​

  • IMGPROXY_BUGSNAG_KEY: Bugsnag API key. When provided, enables error reporting to Bugsnag.
  • IMGPROXY_BUGSNAG_STAGE: the Bugsnag stage to report to. Default: production

Honeybadger​

  • IMGPROXY_HONEYBADGER_KEY: the Honeybadger API key. When provided, enables error reporting to Honeybadger.
  • IMGPROXY_HONEYBADGER_ENV: the Honeybadger env to report to. Default: production

Sentry​

  • IMGPROXY_SENTRY_DSN: Sentry project DSN. When provided, enables error reporting to Sentry.
  • IMGPROXY_SENTRY_ENVIRONMENT: the Sentry environment to report to. Default: production
  • IMGPROXY_SENTRY_RELEASE: the Sentry release to report to. Default: imgproxy@{imgproxy version}

Airbrake​

  • IMGPROXY_AIRBRAKE_PROJECT_ID: an Airbrake project id
  • IMGPROXY_AIRBRAKE_PROJECT_KEY: an Airbrake project key
  • IMGPROXY_AIRBRAKE_ENVIRONMENT: the Airbrake environment to report to. Default: production

Log​

  • IMGPROXY_LOG_FORMAT: the log format. The following formats are supported:
    • pretty: (default) colored human-readable format
    • structured: machine-readable format
    • json: JSON format
    • gcp: Google Cloud Logging agent compliant format
  • IMGPROXY_LOG_LEVEL: the log level. The following levels are supported error, warn, info and debug. Default: info

imgproxy can send logs to syslog, but this feature is disabled by default. To enable it, set IMGPROXY_SYSLOG_ENABLE to true:

  • IMGPROXY_SYSLOG_ENABLE: when true, enables sending logs to syslog.
  • IMGPROXY_SYSLOG_LEVEL: the maximum log level to send to syslog. Known levels are: crit, error, warning and info. Default: info
  • IMGPROXY_SYSLOG_NETWORK: the network that will be used to connect to syslog. When blank, the local syslog server will be used. Known networks are tcp, tcp4, tcp6, udp, udp4, udp6, ip, ip4, ip6, unix, unixgram and unixpacket. Default: blank
  • IMGPROXY_SYSLOG_ADDRESS: the address of the syslog service. Not used if IMGPROXY_SYSLOG_NETWORK is blank. Default: blank
  • IMGPROXY_SYSLOG_TAG: the specific syslog tag. Default: imgproxy
info

imgproxy always uses structured log format for syslog.

Licensing​

  • IMGPROXY_LICENSE_KEY: pro the imgproxy Pro license key. When not provided, imgproxy Pro will run in development mode with a limit of 100 requests per minute. Default: blank
  • IMGPROXY_LICENSE_DEVELOPMENT_MODE: pro when true, enables development mode even if IMGPROXY_LICENSE_KEY is provided. In development mode, imgproxy Pro will run with a limit of 100 requests per minute but won't meter the license usage. Default: false
info

If you bought imgproxyPro in a cloud marketplace (like AWS Marketplace), you don't need to set IMGPROXY_LICENSE_KEY. You can still use IMGPROXY_LICENSE_DEVELOPMENT_MODE to enable development mode for local testing.

Memory usage tweaks​

danger

We highly recommended reading the Memory usage tweaks guide before changing these settings.

  • IMGPROXY_DOWNLOAD_BUFFER_SIZE: the initial size (in bytes) of a single download buffer. When set to zero, initializes empty download buffers. Default: 0
  • IMGPROXY_FREE_MEMORY_INTERVAL: the interval (in seconds) at which unused memory will be returned to the OS. Default: 10
  • IMGPROXY_BUFFER_POOL_CALIBRATION_THRESHOLD: the number of buffers that should be returned to a pool before calibration. Default: 1024
  • IMGPROXY_MALLOC: (Docker only) malloc implementation to use. The following implementations are supported:

Miscellaneous​

  • IMGPROXY_ARGUMENTS_SEPARATOR: a string that will be used as a processing/info options arguments' separator. Default: :
  • IMGPROXY_USE_LINEAR_COLORSPACE: when true, imgproxy will process images in linear colorspace. This will slow down processing. Note that images won't be fully processed in linear colorspace while shrink-on-load is enabled (see below).
  • IMGPROXY_DISABLE_SHRINK_ON_LOAD: when true, disables shrink-on-load for JPEGs and WebP files. Allows processing the entire image in linear colorspace but dramatically slows down resizing and increases memory usage when working with large images.
  • IMGPROXY_STRIP_METADATA: when true, imgproxy will strip all metadata (EXIF, IPTC, etc.) from JPEG and WebP output images. Default: true
  • IMGPROXY_KEEP_COPYRIGHT: when true, imgproxy will not remove copyright info while stripping metadata. Default: true
  • IMGPROXY_STRIP_METADATA_DPI: pro the DPI metadata value that should be set for the image when its metadata is stripped. Default: 72.0
  • IMGPROXY_STRIP_COLOR_PROFILE: when true, imgproxy will transform the embedded color profile (ICC) to sRGB and remove it from the image. Otherwise, imgproxy will try to keep it as is. Default: true
  • IMGPROXY_AUTO_ROTATE: when true, imgproxy will automatically rotate images based on the EXIF Orientation parameter (if available in the image meta data). The orientation tag will be removed from the image in all cases. Default: true
  • IMGPROXY_ENFORCE_THUMBNAIL: when true and the source image has an embedded thumbnail, imgproxy will always use the embedded thumbnail instead of the main image. Currently, only thumbnails embedded in heic and avif are supported. Default: false
  • IMGPROXY_RETURN_ATTACHMENT: when true, response header Content-Disposition will include attachment. Default: false
  • IMGPROXY_HEALTH_CHECK_MESSAGE: pro the content of the health check response. Default: imgproxy is running
  • IMGPROXY_HEALTH_CHECK_PATH: an additional path of the health check. Default: blank