Routing

Vercel's CDN evaluates routing rules on every request before checking any cache or invoking your functions. You can define rules in your framework configuration, in vercel.json or vercel.ts, or as project-level routing rules from the dashboard. Project-level rules support the same core actions as deployment-level routes, with a few exceptions like Routing Middleware.

Requests flow through multiple routing layers in a fixed order. Each layer can modify, redirect, or terminate the request before it reaches the next step.

Project Routes are project-level routing rules you configure from the dashboard or API. They run after bulk redirects and before your deployment's own routes. This means you can add, change, or remove rules without deploying new code.

Redirects send the visitor's browser to a different URL with an HTTP status code (301, 302, 307, or 308). The visitor sees the new URL in their address bar.

Use redirects when you need to:

• Preserve SEO after renaming or moving pages
• Enforce HTTPS or add a trailing slash
• Redirect users based on locale or region
• Handle domain migrations

You can define redirects in vercel.json or through your framework's configuration. For large-scale URL changes, bulk redirects let you upload thousands of rules from a CSV file.

Same-application rewrites map a public URL to a different page or route inside your Vercel project. The visitor's browser still shows the original URL.

Use internal rewrites when you need to:

• Serve different content at the same URL (A/B testing, feature flags)
• Create clean public URLs that map to dynamic routes
• Maintain backward-compatible URLs after restructuring your app

{
  "rewrites": [
    { "source": "/blog/:slug", "destination": "/posts/:slug" }
  ]
}

External rewrites forward requests to a different backend or API outside your Vercel project. The visitor's browser still shows your domain, while the CDN proxies the request to the external origin.

Use external rewrites when you need to:

• Proxy API requests to an external backend under your domain
• Migrate to Vercel incrementally by routing some paths to your existing infrastructure
• Serve content from a headless CMS or third-party service at your own URL

{
  "rewrites": [
    { "source": "/api/:path*", "destination": "https://api.example.com/:path*" }
  ]
}

Vercel can also cache responses from external origins to reduce load on your backend.

• Redirects
• Configuration redirects
• Bulk redirects
• Rewrites
• Project-level routing rules
• Monitoring and logs
• Runtime logs