Resize Fit Mode fit

The fit parameter controls how the output image is fit to its target dimensions after resizing, and how any background areas will be filled

Valid values are clamp, clip, crop, facearea, fill, fillmax, max, min, and scale. The default value is clip.

fit=clamp

Resizes the image to fit within the width and height dimensions without cropping or distorting the image, and the remaining space is filled with extended pixels from the edge of the image. The resulting image will match the constraining dimensions. The pixel extension is called an affine clamp, hence the value name, “clamp”.

Example of how clamp works

fit=clip

Default. Resizes the image to fit within the width and height boundaries without cropping or distorting the image. The resulting image will match one of the constraining dimensions, while the other dimension is altered to maintain the same aspect ratio of the input image.

Example of how clip works

  • Unset: This is the original image at 300×200 with no parameters applied. clip is the default, so is not necessary.

    original image

  • fit=clip&w=100&h=100: Attempting to resize this image to be 100×100 with a fit mode of clip will result in an image that is 100×67 because the aspect ratio of the original image is maintained.

    Clipped image

fit=crop

Resizes the image to fill the width and height dimensions and crops any excess image data. The resulting image will match the width and height constraints without distorting the image. It’s used in conjunction with the the crop parameter, which controls how the image is cropped. Both the w and h parameters will also need to be set.

Example of how crop works

  • Unset: Default. This is the original image at 300×200 size with no parameters applied.

    original image

  • fit=crop&w=300&h=100: Resizing the image to 300×100 with fit=crop will fit the image exactly to those dimensions.

    Cropped image

  • fit=crop&w=200&h=200: Setting an equal value for width and height along with fit=crop will always result in a square image. To adjust the position of the content in a cropped image, please review the crop mode parameter.

    Image cropped to square

fit=facearea

Finds the area containing all faces, or a specific face in an image, and scales it to specified width and height dimensions. Can be used in conjunction with faceindex to identify a specific face, as well as facepad to include additional padded area around the face to zoom out from the immediate area around the faces.

Example of how facearea works

  • Unset: Default. This is the entire image, with no face area cropping, resized to 300×200.

    Original image

  • fit=facearea&w=300&h=200: Crops and resizes the image to 300×200, with the faces centered as closely as possible. The output is the correct requested size, depending on the output aspect ratio and face area availability.

    Cropped image, with faces centered

  • fit=facearea&faceindex=2&facepad=1.5&w=300&h=300: Crops and resizes the image to 300×300, making use of the faceindex and facepad parameters to select a face within the image and zoom in.

    Image with one face selected

fit=fill

Resizes the image to fit within the requested width and height dimensions while preserving the original aspect ratio and without discarding any original image data. Excess space is filled with a solid color or blurred version of the image. The resulting image exactly matches the requested dimensions.

Example of how fill works Fill legend

To achieve these characteristics while also preventing an image from being sized beyond its original dimensions, see fit=fillmax.

  • Unset: w=250&h=250. Because no fit mode has been set, a request to resize a 300×200 image to 250×250 results in a 250×167 output image. The original aspect ratio is preserved, but the resulting image does not exactly match the requested dimensions.

    Resized without fit mode

  • Solid: fit=fill&fill=solid&fill-color=360036&w=250&h=250. Image resized to 250×250, with original image automatically centered and excess space filled with specified solid color.

    Resized with fit=fill and fill=solid

    If no fill-color is specified, the excess space will be white or transparent, depending on whether the image output format supports transparency.

  • Blur: fit=fill&fill=blur&w=250&h=250. After resize to 250×250, excess space is filled with a blurred version of the original image. Behavior of fill=blur is identical to the blur parameter but applied only to the excess space.

    Resized with fit=fill and fill=blur

fit=fillmax

Resizes the image to fit within the requested width and height dimensions while preserving the original aspect ratio and without discarding any original image data. If the requested width or height exceeds that of the original, the original image remains the same size. The excess space is filled with a solid color or blurred version of the image. The resulting image exactly matches the requested dimensions.

Example of how fillmax works Fill legend

Note that fit=fillmax places constraints on upscaling the original image; fit=fill does not, which may sometimes result in lower image quality.

  • Solid: fit=fillmax&fill=solid&fill-color=28285D&w=400&h=300. Original 300×200 image resized to 400×300, larger than the original image. Original image is automatically centered and excess space is filled with specified solid color.

    Resized with fit=fillmax and fill=solid

    If no fill-color is specified, the excess space will be white or transparent, depending on whether the image output format supports transparency.

  • Blur: fit=fillmax&fill=blur&w=400&h=300. After resize to 400×300, excess space is filled with a blurred version of the original image. Behavior of fill=blur is identical to the blur parameter but applied only to the excess space.

    Resized with fit=fillmax and fill=blur

fit=max

Resizes the image to fit within the width and height dimensions without cropping or distorting the image, but will not increase the size of the image if it is smaller than the output size. The resulting image will maintain the same aspect ratio of the input image.

Example of how max works Max legend

  • Unset: Default. This is the original image at 300×200 with no parameters applied.

    Original image

  • fit=max&w=500&h=300: Attempting to resize to 500×300 will result in an image that is 300×200, the original dimensions of the image, applying max will not scale up the image.

    Image with fit=max

  • fit=max&w=200&h=400: Attempting to resize to 200×400 will result in a 200×133 image. This behavior is somewhat similar to clip.

    Image resized outside of bounds

fit=min

Resizes and crops the image to match the aspect ratio of the requested width and height. Will not exceed the original width and height of the image.

Example of how min works

  • Unset: This is the original image at 300×200 with no parameters applied.

    Original image

  • fit=min&w=500&h=200: Attempting to resize to 500×200 will result in an image that is 300×120, The requested aspect ratio is maintained and the image will be cropped, but the image will not exceed its original size.

    image with fit=min

  • fit=min&w=200&h=400: Attempting to resize to 200×400 will result in a 100×200 image. The requested aspect ratio is maintained and the image will be cropped, but the image will not exceed its original size.

    Image resized outside of bounds

fit=scale

Scales the image to fit the constraining dimensions exactly. The resulting image will fill the dimensions, and will not maintain the aspect ratio of the input image.

Example of how scale works