This guide describes the advanced URL format that allows the use of all the imgproxy features. Read our [Generating the URL (Basic)](generating_the_url_basic.md) guide to learn about the _basic_ URL format that is compatible with imgproxy 1.x.
Once you set up your [URL signature](configuration.md#url-signature), check out the [Signing the URL](signing_the_url.md) guide to know how to sign your URLs. Otherwise, use any string here.
The list of processing options does not define imgproxy's processing pipeline. Instead, imgproxy already comes with a specific, built-in image processing pipeline for the maximum performance. Read more about it in the [About processing pipeline](about_processing_pipeline.md) guide.
Meta-option that defines the [resizing type](#resizing-type), [width](#width), [height](#height), [enlarge](#enlarge), and [extend](#extend). All arguments are optional and can be omitted to use their default values.
Meta-option that defines the [width](#width), [height](#height), [enlarge](#enlarge), and [extend](#extend). All arguments are optional and can be omitted to use their default values.
*`fill`: resizes the image while keeping aspect ratio to fill given size and cropping projecting parts;
*`auto`: if both source and resulting dimensions have the same orientation (portrait or landscape), imgproxy will use `fill`. Otherwise, it will use `fit`.
Defines the width of the resulting image. When set to `0`, imgproxy will calculate the resulting width using the defined height and source aspect ratio.
* When `extend` is set to `1`, `t` or `true`, imgproxy will extend the image if it is smaller than the given size.
*`gravity`_(optional)_ accepts the same values as [gravity](#gravity) option, except `sm`. When `gravity` is not set, imgproxy will use `ce` gravity without offsets.
*`gravity:sm` - smart gravity. `libvips` detects the most "interesting" section of the image and considers it as the center of the resulting image. Offsets are not applicable here;
*`gravity:fp:%x:%y` - focus point gravity. `x` and `y` are floating point numbers between 0 and 1 that define the coordinates of the center of the resulting image. Treat 0 and 1 as right/left for `x` and top/bottom for `y`.
Defines an area of the image to be processed (crop before resize).
*`width` and `height` define the size of the area. When `width` or `height` is set to `0`, imgproxy will use the full width/height of the source image.
*`gravity`_(optional)_ accepts the same values as [gravity](#gravity) option. When `gravity` is not set, imgproxy will use the value of the [gravity](#gravity) option.
**⚠️Warning:** Trimming requires an image to be fully loaded into memory. This disables scale-on-load and significantly increases memory usage and processing time. Use it carefully with large images.
**📝Note:** Trimming of animated images is not supported.
When set, imgproxy will fill the resulting image background with the specified color. `R`, `G`, and `B` are red, green and blue channel values of the background color (0-255). `hex_color` is a hex-coded value of the color. Useful when you convert an image with alpha-channel to JPEG.
Meta-option that defines the [brightness](#brightness), [contrast](#contrast), and [saturation](#saturation). All arguments are optional and can be omitted to use their default values.
When set, imgproxy will adjust contrast of the resulting image. `contrast` is a positive floating point number, where `1` keeps the contrast unchanged.
When set, imgproxy will adjust saturation of the resulting image. `saturation` is a positive floating point number, where `1` keeps the saturation unchanged.
As an approximate guideline, use 0.5 sigma for 4 pixels/mm (display resolution), 1.0 for 12 pixels/mm and 1.5 for 16 pixels/mm (300 dpi == 12 pixels/mm).
*`x_offset`, `y_offset` - (optional) specify watermark offset by X and Y axes. Not applicable to `re` position;
*`scale` - (optional) floating point number that defines watermark size relative to the resulting image size. When set to `0` or omitted, watermark size won't be changed.
When set, imgproxy will prepend `<style>` node with provided content to the `<svg>` node of source SVG image. `%style` is url-safe Base64-encoded CSS-style.
Allows redefining JPEG saving options. All arguments have the same meaning as [Advanced JPEG compression](configuration.md#advanced-jpeg-compression) configs. All arguments are optional and can be omitted.
Allows redefining PNG saving options. All arguments have the same meaning as [Advanced PNG compression](configuration.md#advanced-png-compression) configs. All arguments are optional and can be omitted.
Allows redefining GIF saving options. All arguments have the same meaning as [Advanced GIF compression](configuration.md#advanced-gif-compression) configs. All arguments are optional and can be omitted.
Cache buster doesn't affect image processing but it's changing allows to bypass CDN, proxy server and browser cache. Useful when you have changed some things that are not reflected in the URL like image quality settings, presets or watermark data.
It's highly recommended to prefer `cachebuster` option over URL query string because the option can be properly signed.
Extension specifies the format of the resulting image. At the moment, imgproxy supports only `jpg`, `png`, `webp`, `gif`, `ico`, and `tiff`, them being the most popular and useful image formats.
The extension part can be omitted. In this case, imgproxy will use source image format as resulting one. If source image format is not supported as resulting, imgproxy will use `jpg`. You also can [enable WebP support detection](configuration.md#webp-support-detection) to use it as default resulting format when possible.
Signed imgproxy URL that uses `sharp` preset, resizes `http://example.com/images/curiosity.jpg` to fill `300x400` area with smart gravity without enlarging, and then converts the image to `png`:
