Migrating from gatsby-image to gatsby-plugin-image

This document is provided to help users of gatsby-image migrate to using gatsby-plugin-image.

Note that you can use both packages at the same time. You may need to in situations where you’re using a gatsby-image-compatible CMS as a data source, and that CMS plugin has not yet updated to a version compatible with the new API.

If you’re looking for other documentation on the new plugin, see:

• How-To Guide: Using the beta Gatsby Image plugin
• Reference Guide: Gatsby Image plugin

What changed?

New Syntax

The new plugin requires significant syntax changes. We’ve provided a codemod to help you migrate, but this section will explain the changes.

Import change

Previously, GatsbyImage was the default export from gatsby-image. With gatsby-plugin-image, the component is now a named export.

GraphQL changes

This is one of the bigger changes. There are no more fragments to use. Instead, things like layout and format are passed as arguments to the resolver.

This is the previous syntax.

The new syntax looks like this. The fragment is removed in favor of gatsbyImageData, which is used for all images. Previous configuration options - such as fixed vs. fluid, WebP generation, and placeholder type - are passed as arguments to the resolver.

Other changes to the available argument structure are in the section on API changes.

Component changes

The last change is to the JSX component. The import name is potentially different, and the query result is also different.

API Changes

In addition to the syntax changes for using gatsby-plugin-image, there are also changes to the API that affect the resolver arguments (and the new StaticImage component).

fluid

The fluid image type has been deprecated in favor of two alternatives.

The first is an image type called fullWidth. This image is designed to be used for things like hero images that span the full width of the screen, and generates image sizes accordingly. Instead of passing something like maxWidth, it takes an array called breakpoints that will generate images designed for those screen sizes. In most cases you will not need to provide these, as there are default values that work for most sites. Note that like the old fluid layout, fullWidth images will expand to fit the width of their container, even if that width is larger than the source image.

The second is a responsive image type called constrained that will shrink with its container and generates smaller images, but nothing larger than the original image source size. Additionally, you can pass width and/or height to limit the displayed image to that size. In this case, larger images may be generated for high-density screens.

maxWidth

maxWidth and maxHeight are deprecated for all image types. For constrained and fixed images, use width and height. For fullWidth images, look at the breakpoints option.

aspectRatio

aspectRatio is a new argument that takes a number (or fraction). If you pass it without also passing in width or height, it will default to using the source image width and then adjusting the height to the correct aspect ratio. Alternatively, you can pass your own width or height and it will set the other dimension. Passing both height and width will cause aspectRatio to be ignored in favor of the inferred aspect ratio.

formats

Previously, images generated their own type by default, e.g. JPG, PNG, etc. You could also generate WebP images when using the appropriate fragment. This is now controlled using the formats argument. This field takes an array, [AUTO, WEBP] by default, where AUTO means the same format as the source image.AVIF is now also a valid format.

Options nested inside objects

Previously, transformations like grayscale and quality options such as pngQuality were top level query arguments. This has changed.

grayscale now exists within the transformOptions argument, and pngQuality becomes quality inside pngOptions. The traceSVG object is now tracedSVGOptions. See the gatsby-plugin-image Reference Guide for specifics.

Breaking changes

Due to the changes to gatsby-plugin-image, there is some functionality that is no longer supported.

1. GatsbyImage is no longer a class component and therefore cannot be extended. You can use composition instead.

2. fluid images no longer exist, and the fullWidth replacement does not take maxWidth or maxHeight.

3. The art direction API has changed, see the gatsby-plugin-image reference guide for specifics.

4. The component no longer takes a decomposed object, and the following code is not valid. You should avoid accessing or changing the contents of the gatsbyImageData object, as it is not considered to be a public API, so can be changed without notice.

How to Migrate

1. Install and update dependencies.

2. Configure plugins.

3. Run the codemod.

   Note that if you need to do a partial migration, e.g. because you’re using a CMS that doesn’t yet support the new plugin alongside local image files, you’ll want to make use of the optional-path to run against individual files.

   Without an optional-path, the codemod will run against all the files in your current directory, so running it in root is recommended. It will ignore node_modules, .cache, and public automatically. It will also respect any local Babel configuration in your project. The codemod is designed to run against files with the extensions .ts, .js, .tsx, and .jsx. If this does not cover your project, or you require other customizations, see the section on using jscodeshift.

   Due to the API changes, the codemod is not a pure 1:1 mapping. There are some changes introduced.

   • Fluid images will map to either fullWidth or constrained images. This decision is made based on the existence of maxWidth and its value. If maxWidth does not exist, it will be a fullWidth image. If it does, and the maxWidth is less than 1000, it will be a constrained image, otherwise a fullWidth image. fullWidth images do not retain their maxWidth or maxHeight fields; constrained images do, as width and height.

   • All images will generate WebP.

   The codemod will output warnings in a number of different scenarios and point you to the file in question so you can inspect the changes manually.

4. Consider manual changes.

• For images using static query, you should move to use the StaticImage component instead. This component takes src, which can be a remote image URL or a relative path to an image. Make sure you’ve installed gatsby-source-filesystem if you’re going to use this component.

• You may also consider refactoring code to make use of the getImage helper function.

• Finally, if you were previously using src, e.g. for an SEO component, you’ll want to use the getSrc helper function as the internal structure of the return object has changed.

jscodeshift

This section is for people who need to run the codemod with extra flags exposed by jscodeshift, e.g. to transform file types other than those with extensions .js, .ts, .tsx, or .jsx.

1. Install jscodeshift.

2. Install the codemods package in your project.

3. Run the codemod using jscodeshift.

See the jscodeshift docs for all the available flags.