Storage Image Transformations

Transform images with Storage

Supabase Storage offers the functionality to optimize and resize images on the fly. Any image stored in your buckets can be transformed and optimized for fast delivery.

Get a public URL for a transformed image#

Our client libraries methods like getPublicUrl and createSignedUrl support the transform option. This returns the URL that serves the transformed image.

An example URL could look like this:

https://project_id.supabase.co/storage/v1/render/image/public/bucket/image.jpg?width=500&height=600

Signing URLs with transformation options#

To share a transformed image in a private bucket for a fixed amount of time, provide the transform option when you create the signed URL:

The transformation options are embedded into the token attached to the URL — they cannot be changed once signed.

Downloading images#

To download a transformed image, pass the transform option to the download function.

Automatic image optimization (WebP)#

When using the image transformation API, Storage will automatically find the best format supported by the client and return that to the client, without any code change. For instance, if you use Chrome when viewing a jpeg image and using transformation options, you'll see that images are automatically optimized as webp images.

As a result, this will lower the bandwidth that you send to your users and your application will load much faster.

Disabling automatic optimization:

In case you'd like to return the original format of the image and opt-out from the automatic image optimization detection, you can pass the format=origin parameter when requesting a transformed image, this is also supported in the JavaScript SDK starting from v2.2.0

Next.js loader#

You can use Supabase Image Transformation to optimize your Next.js images using a custom Loader.

To get started, create a supabase-image-loader.js file in your Next.js project which exports a default function:

In your nextjs.config.js file add the following configuration to instruct Next.js to use our custom loader

At this point you are ready to use the Image component provided by Next.js

Transformation options#

We currently support a few transformation options focusing on optimizing, resizing, and cropping images.

Optimizing#

You can set the quality of the returned image by passing a value from 20 to 100 (with 100 being the highest quality) to the quality parameter. This parameter defaults to 80.

Example:

Resizing#

You can use width and height parameters to resize an image to a specific dimension. If only one parameter is specified, the image will be resized and cropped, maintaining the aspect ratio.

Modes#

You can use different resizing modes to fit your needs, each of them uses a different approach to resize the image:

Use the resize parameter with one of the following values:

• cover : resizes the image while keeping the aspect ratio to fill a given size and crops projecting parts. (default)

• contain : resizes the image while keeping the aspect ratio to fit a given size.

• fill : resizes the image without keeping the aspect ratio.

Example:

Limits#

• Width and height must be an integer value between 1-2500.
• The image size cannot exceed 25MB.
• The image resolution cannot exceed 50MP.

Supported image formats#

Self hosting#

Our solution to image resizing and optimization can be self-hosted as with any other Supabase product. Under the hood we use Imgproxy

Imgproxy configuration:#

Simply deploy an imgproxy container with the following configuration:

Note: make sure that this service can only be reachable within an internal network and not exposed to the public internet

Storage API configuration:#

Once Imgproxy is deployed we need to configure a couple of environment variables in your self-hosted storage-api service as follows: