Resize & Fit
Width and Height
Section titled “Width and Height”Use w and h to set the output dimensions in pixels.
| Param | Type | Max | Description |
|---|---|---|---|
w | integer | 8192 | Output width in pixels |
h | integer | 8192 | Output height in pixels |
You can specify just w, just h, or both together.
Only width
Section titled “Only width”The height is calculated automatically to preserve the aspect ratio.
/w=400/https://example.com/photo.jpgA 1200x800 source image becomes 400x267.
Only height
Section titled “Only height”The width is calculated automatically to preserve the aspect ratio.
/h=300/https://example.com/photo.jpgA 1200x800 source image becomes 450x300.
Both width and height
Section titled “Both width and height”When both are specified, the fit parameter controls how the image is resized to fill the given box.
/400x400/https://example.com/photo.jpgFit Modes
Section titled “Fit Modes”The fit parameter controls behavior when both w and h are provided.
| Value | Description |
|---|---|
contain | Scale to fit within the box, preserving aspect ratio. No cropping. Dimensions may be smaller than requested. (default) |
cover | Scale to fill the entire box, preserving aspect ratio. May crop edges. Output is always the exact requested size. |
crop | Hard crop to the exact dimensions without scaling. No aspect ratio preservation. |
contain (default)
Section titled “contain (default)”The image is scaled down so it fits entirely within the w x h box. The output image will not exceed either dimension, and no pixels are cropped.
/400x400,contain/https://example.com/photo.jpgA 1200x800 source image becomes 400x267 - it fits within the 400x400 box while keeping the full image visible.
The image is scaled up or down so it completely fills the w x h box. Excess pixels along one edge are cropped. The output is always exactly w x h.
/400x400,cover/https://example.com/photo.jpgA 1200x800 source image becomes 400x400 - cropped to a square filling the box.
The image is hard-cropped to the exact dimensions starting from the top-left, without any scaling. Use this when you need a precise pixel cutout.
/400x400,crop/https://example.com/photo.jpgA 1200x800 source image becomes 400x400 - the top-left 400x400 pixels of the original, with no resizing applied.
Dimension Limits
Section titled “Dimension Limits”The maximum value for both w and h is 8192 pixels. Requests exceeding this limit will be rejected.
Examples Summary
Section titled “Examples Summary”| Source | Params | Output | Notes |
|---|---|---|---|
| 1200x800 | w=400 | 400x267 | Width only, height scaled proportionally |
| 1200x800 | h=300 | 450x300 | Height only, width scaled proportionally |
| 1200x800 | 400x400 | 400x267 | Both, contain (default) - fits within box |
| 1200x800 | 400x400,contain | 400x267 | Explicit contain - same as above |
| 1200x800 | 400x400,cover | 400x400 | Fills box, crops edges |
| 1200x800 | 400x400,crop | 400x400 | Hard crop from top-left, no scaling |