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Legacy Next.js on Netlify

Legacy Next.js Runtime

The information on this page applies to Next.js version 10-13.4 and Netlify Next.js Runtime v4, which is currently in maintenance support.

Visit our Next.js adapter docs for info on newer versions of Next.js.

Next.js is a React-based open source framework that provides a hybrid static / server-side rendered model for enterprise-grade sites and applications.

# Key features

These Next.js features provide important benefits for sites and apps, including those built and deployed with Netlify.

  • Page routing. Next.js boasts a file system-based routing structure. Organizing files and subdirectories within a pages directory automatically results in corresponding routes.

  • Automatic API endpoints. For simpler API management, any file added to the pages/api directory is treated as an API endpoint with a corresponding API route. Netlify also offers advanced API routes.

  • Preview mode. Netlify supports rendering a draft page from any data-fetching solution instead of building a statically-generated page to preview. This preview mode functionality eliminates waiting for a build to run before previewing new content.

  • Hybrid or static. You can use a hybrid approach to generate content, choosing between server-side rendering or static generation on a per-page basis, or you can use next export to generate a completely static site.

  • Image optimization. The next/image component allows you to automatically optimize images for your site on-demand, as they’re requested by users. On Netlify, next/image uses ipx and On-demand Builders by default. For further optimization, you can route image requests through Netlify Image CDN.

  • Incremental Static Regeneration (ISR). ISR on Netlify works with On-demand Builders to revalidate pages as needed without rebuilding your entire site. This enables faster builds, especially for very large projects.

  • Internationalization. Netlify supports Next.js internationalized routing functionality for locale-specific options.

# Next.js Runtime v4

Netlify’s Next.js Runtime configures your site on Netlify to enable key Next.js functionality. It automatically generates serverless functions that handle server-side rendered (SSR) pages, incremental static regeneration (ISR), images, and Next.js features.

# Redirects and rewrites

Next.js Runtime supports Next.js rewrites and redirects. These are defined in your next.config.js file and support some features that are not included in Netlify redirects and rewrites.

We recommend using Netlify redirects when possible because they are faster to evaluate. Rewrites are a little different. Generally with Next.js Runtime, you should use Next.js rewrites instead of Netlify rewrites.

Avoid root-level rewrite

Do not add a rewrite from the site root (such as from = "/") in netlify.toml or _redirects. Your root-level rewrite would take precedence over Next.js Runtime’s own rewrites and break routing on your site.

Learn more on the Next.js redirects and rewrites on Netlify page.

# Middleware

Next.js Runtime supports Middleware, a feature in which functions run before a request has finished processing. Regular Next.js Middleware can be used to modify the request or replace the response. For example, it can change headers, rewrite the request path, or return a different response entirely.

Beyond regular Middleware, Netlify’s Next.js Advanced Middleware, available in the @netlify/next library, gives improved access to requests and responses. This is similar to Netlify Edge Functions, but with some additional Next.js-specific helpers.

Learn more on the Next.js Middleware on Netlify page.

# Custom Headers

Next.js Runtime supports Next.js custom headers. Custom headers work for SSR, static site generation (SSG), ISR pages, and IPX images. There’s no need to add custom headers in the Netlify configuration.

# Optimize images with next/image

next/image includes built-in performance optimization, like optimizing image size. Next.js Runtime uses an On-demand Builder function to handle image processing and caching. This processes an image on the first request which means it may take longer to load, but then the generated image is cached and served as a static file to future visitors for faster response times.

# next/image and Netlify Image CDN

For further optimization, route next/image requests through Netlify Image CDN by adding the following redirect:

# netlify.toml
[[redirects]]
from = '/_next/image/*'
query = { q = ':quality', url = ':url', w = ':width' }
to = '/.netlify/images?url=:url&w=:width&q=:quality'
status = 200
force = true

Netlify Image CDN handles content negotiation to use the most efficient image format for the requesting client. We inspect the Accept header for content negotiation with the following logic:

  1. use avif if accepted
  2. otherwise, use webp if accepted
  3. if neither is accepted, use the original format

# Limitations

  • Large functions. During deployment, each unzipped function bundle is limited to 250 MB in size. Some functions generated by Next.js Runtime may exceed that limit and throw an error. The troubleshooting page has more information.

# Suggested configuration values

When you link a repository for a Next.js project, Netlify provides a suggested build command and publish directory: next build and .next.

If you’re using the CLI to run Netlify Dev for a local development environment, Netlify suggests a dev command and port: next and 3000.

You can override suggested values or set them in a configuration file instead, but suggested values from automatic framework detection may help simplify the process of setting up a Next.js site on Netlify.

For manual configuration, check out the typical build settings for Next.js.

serverless target deprecated

The serverless and experimental-serverless-trace targets are deprecated in Next 12, and all builds with Next.js Runtime use the default server target. If you previously set the target in your next.config.js, you should remove it.

# Edge Functions

Edge Functions connect the Netlify platform and workflow with an open runtime standard at the network edge. This enables you to build fast, personalized web experiences with an ecosystem of development tools.

For different ways to use Edge Functions with Next.js, check out the React Server Components and Edge middleware examples. You can also browse the full library of reference examples.

Note that the Edge Functions feature has limits that you should be aware of. For example, edge functions won’t work for sites with Split Testing enabled.

# NextAuth.js support

NextAuth.js is a complete open source authentication solution for Next.js applications. When Next.js Runtime detects the next-auth package in your build, it automatically sets the NEXTAUTH_URL environment variable to your site’s canonical URL. If a custom base path is specified as part of your site configuration, this is included as part of the NEXTAUTH_URL.

To use NextAuth.js, you need to set a NEXTAUTH_SECRET environment variable in the Netlify UI. This gives your site’s builds secure access to your NEXTAUTH_SECRET and value. Note that if you have the option to set specific scopes for your environment variables, the scope must include Builds to be available during the build process.

# pnpm support

If you’re planning to use pnpm with Next.js to manage dependencies, you must do one of the following:

  • Set a PNPM_FLAGS environment variable with a value of --shamefully-hoist. This appends a --shamefully-hoist argument to the pnpm install command that Netlify runs.

  • Enable public hoisting by adding an .npmrc file in the root of your project with this content:

    public-hoist-pattern[]=*

Learn more about using pnpm on Netlify.

# Troubleshooting

If you run into issues running a Next.js app on Netlify, check out our troubleshooting page. You can also visit the Netlify Support Forums to see if others have encountered similar issues.

# More resources

← Next.js Middleware →