Formatters & Code

Vercel Redirects CSV Validator & JSON Rule Checker

Validate Vercel redirects CSV and JSON files locally. Check leading slashes, status codes, query syntax traps, circular loops, and test route matching.

Redirect rules

Upload Vercel Redirects File (CSV or JSON)

Drop your redirects CSV or vercel.json file here

or click to browse your computer (all checks run locally, up to 10 MB and 50,000 rules)

Or Paste Redirects (CSV, JSON, or Two-Column Mapping)

Test a redirect route

Test Route Simulator

Test any URL path against your active redirect rules to preview which pattern matches and where it redirects.

Results

What the result means

This tool inspects your redirect rules against Vercel CLI bulk upload and vercel.json deployment specifications without sending sensitive URLs or website paths to remote servers. Vercel enforces strict routing parameters: source paths must begin with a leading slash, cannot include query parameters or hash fragments, and only permit HTTP status codes 301, 302, 307, or 308. The validator parses your CSV or JSON, checks named parameter captures and wildcards, highlights self-redirects and circular loops that trigger browser errors, identifies multi-hop redirect chains, and includes a live routing simulator to test how incoming URLs resolve before committing configuration changes to production.

Related tools

Guides

Questions

Why does Vercel reject redirect sources with query strings?

The Vercel routing engine separates path matching from query parameters. The source property strictly matches request pathnames. To match specific query parameters, Vercel requires defining a "has" condition array in vercel.json.

Which HTTP redirect status code should I use for permanent migrations?

Vercel recommends HTTP 308 for permanent redirects because it preserves the original HTTP request method, unlike HTTP 301 which legacy browsers may rewrite from POST to GET.

Can this validator convert simple two-column migration spreadsheets into Vercel format?

Yes. Paste or upload any two-column CSV mapping old paths to new paths, and the tool will automatically convert them into Vercel's official 5-column CSV format with standard status codes and parameter options.