Analyze the HTTP status code and headers of a response and get an explanation of whether it is correct for the situation.
Validation
Open tool
Response Validation Tools
A response can be 200 OK and still be wrong. These analyzers look at the parts of a response that quietly break clients and security reviews: cookie flags, caching directives, security headers such as CSP and HSTS, and the status code itself.
The contract tools compare what an API actually returns with what it promised — a schema or an earlier response — and flag removed fields, changed types and other breaking changes before consumers find them.
Tools in this category
Parse Set-Cookie headers and check Secure, HttpOnly, SameSite, Domain, Path, expiry and size best practices.
Validation
Open tool
Analyze Cache-Control, Expires, ETag, Last-Modified, Vary and Age headers and explain how browsers and CDNs will cache the response.
Validation
Open tool
Grade HTTP security headers (CSP, HSTS, X-Frame-Options, Referrer-Policy, Permissions-Policy, COOP/CORP) from pasted headers or a public URL.
Validation
Open tool
Validate that an API request/response pair conforms to its OpenAPI contract: path, method, parameters, body and response schema.
Validation
Open tool
Compare an actual API response against an expected contract (example or schema) and report breaking vs non-breaking differences.
Validation
Open tool
Guides
More guides →