Parameters

All transform parameters are optional; out-of-range values are clamped, not rejected.

Param	Type	Range / values	Default	Description
`project`	string	—	required	Project id (allowlist gates access)
`url`	URL	absolute `http`/`https` URL	—	Source image URL when not using the `/img/<source-url>` path form
`w` / `h`	int	1–5000	bounded original	Target width/height (px)
`resize` / `s`	string	`WIDTHxHEIGHT`, `WIDTH`, `xHEIGHT`	—	Compact size alias; explicit `w`/`h` win
`q`	int	30–100	project default	Output quality
`fmt`	enum	`auto` `avif` `webp` `jpeg` `png` `gif` `heif` `tiff` `svg`	`auto`	Output format (`auto` negotiates AVIF/WebP/JPEG)
`fit`	enum	`cover` `contain` `fill` `inside` `outside`	`cover`	How to fit the `w`×`h` box
`position` / `pos` / `gravity`	enum	edges, corners, compass gravities, `entropy`, `attention`	`centre`	Crop anchor for `cover`/`contain`
`dpr`	int	1–3	`1`	Device pixel ratio (multiplies `w`/`h`)
`enlarge`	bool	`1` `true` `yes` `on`	`false`	Allow upscaling past source dimensions
`kernel`	enum	`nearest` `linear` `cubic` `mitchell` `lanczos2` `lanczos3` `mks2013` `mks2021`	`lanczos3`	Resize kernel
`background` / `bg`	color	Sharp color string	—	Fill color for `contain`, `flatten`, `extend`, and arbitrary rotate
`flatten`	bool	`1` `true` `yes` `on`	`false`	Merge alpha onto `background`
`extract` / `crop`	string	`left,top,width,height`	—	Crop an exact source rectangle before resize
`trim`	bool/int	`true` or 0–255	`false`	Trim matching edges; number is threshold
`extend`	string	`all`, `y,x`, `top,right,bottom,left`	—	Add output padding after resize
`extendWith`	enum	`background` `copy` `repeat` `mirror`	`background`	Fill mode for `extend`
`rotate` / `r`	float	-360–360	—	Rotate by degrees after EXIF auto-orient
`flip` / `flop`	bool	`1` `true` `yes` `on`	`false`	Vertical / horizontal mirror
`blur`	int	0–1000	`0`	Gaussian blur sigma
`sharpen`	bool/float	`true` or 0.000001–10	`false`	Apply mild or sigma-based sharpening
`median`	int	1–25	—	Median filter size
`gamma` / `gammaOut`	float	1–3	—	Gamma correction
`negate`	bool	`1` `true` `yes` `on`	`false`	Invert colors
`normalize` / `normalise`	bool	`1` `true` `yes` `on`	`false`	Contrast normalization
`threshold`	int	0–255	—	Convert to black/white threshold
`brightness` / `saturation`	float	0–10	—	Modulate brightness/saturation
`hue`	int	-360–360	—	Hue rotation
`lightness`	float	-100–100	—	Lightness adjustment
`tint`	color	Sharp color string	—	Apply a tint
`grayscale` / `greyscale`	bool	`1` `true` `yes` `on`	`false`	Convert to grayscale
`animated` / `a`	bool	`1` `true` `yes` `on`	`false`	Preserve animated GIF/WebP frames when output supports it

Notes

No upscaling by default. Keenpix never enlarges past the source resolution unless enlarge=1 is set.
Source URL. Put the absolute source URL after /img/, for example /img/https://cdn.example.com/hero.jpg?project=ID&w=1200, or send it as /img/?url=https%3A%2F%2Fcdn.example.com%2Fhero.jpg&project=ID&w=1200.
dpr multiplies the target dimensions — w=400&dpr=2 renders at 800px.
fmt=auto depends on the project's Auto-format setting; when off, auto serves JPEG. Omitting fmt is treated as auto. It is raster negotiation only: SVG origins are rasterized and returned as AVIF, WebP, or JPEG rather than preserved as SVG. An explicit fmt is always honoured and disables browser negotiation for that request. Use explicit fmt values when your CDN cannot cache separate variants by Accept.
Framework format props. Image frameworks often map format="avif" or format="webp" directly to fmt=avif or fmt=webp. Leave those props unset when you want Keenpix to return AVIF or WebP based on browser support.
fmt=svg is explicit only. It returns image/svg+xml only for SVG origins, optimizes them through SVGO, and strips active content. Raster transform modifiers do not apply to SVG output.
q defaults to the project's Default quality (Settings → Pipeline).

Notes

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