API Response Validator
Paste a captured response and its OpenAPI document. Match the actual status and Content-Type to the operation’s contract, then validate the body.
1. OpenAPI document
One pasted JSON or YAML document · 1 MiB maximum · no linked documents are fetched.
OpenAPI document editor3. Captured response body
Paste manually · 256 KiB maximum. JSON and ordinary text are supported.
An empty editor is an empty body, not JSON null.
Response body editor4. Response analysis
Parse a document, select an operation, and validate the pasted response.
Validate a captured API response
Parse one OpenAPI document, find the operation by method, path, operationId, or summary, then enter the actual status, Content-Type, and body. Exact status takes precedence over 1XX–5XX ranges, followed by default. If none matches, the status is undocumented.
Content-Type and body checks
The most specific applicable representation wins: exact media type, type/*, then */*. Parameters are parsed separately. A problem+json body does not match application/json solely because both use JSON. Status selection, media selection, body parsing, and schema validation are reported separately. This is a manual paste workflow; no API request is made.
OpenAPI versions and schema dialects
Response-contract analysis is based on OpenAPI 3.1.x and 3.2.x semantics, including QUERY, additionalOperations, and 3.2 media references. Patch releases share their minor feature line; the exact declared version is shown. OpenAPI 3.0, Swagger 2.0, and future minor lines are recognized but unsupported. This is focused response analysis, not a complete OpenAPI conformance validator.
Schema validation uses Draft 2020-12 assertions with official OAS 3.1 and 3.2 dialect annotations preserved. The document default, jsonSchemaDialect, and supported schema-resource $schema overrides are respected. Custom dialects block affected validation. format, readOnly/writeOnly, discriminator, and serialization annotations do not become additional hard assertions.
Local references and supported bodies
Local Path Item, Response, Media Type (3.2), and schema fragment references are resolved within this pasted document. Component schemas and $defs use their document JSON Pointer scope. Linked documents and remote examples are never fetched. Resource URI resolution using $id, anchors, or dynamic references is outside this adapter and blocks affected validation.
JSON and structured +json payloads are parsed as JSON; ordinary text is passed as a string. XML, YAML response bodies, binary, forms, multipart, SSE, NDJSON, and JSON sequences are unsupported. itemSchema is never used as a complete-body schema. Independent streaming item validation is not supported in Phase 6. Response headers beyond Content-Type, request validation, webhooks, and callbacks are deferred.
Privacy and indexability
Documents and bodies stay in browser memory and run in a bounded worker. Editing a document clears its cached analysis. There is no automatic persistence, backend, analytics, or live endpoint access. Both routes remain noindex, follow and excluded from the sitemap pending launch review.
Official sources checked
OpenAPI Specification 3.1.2 (3.1.2) · OpenAPI Specification 3.2.1 (3.2.1) · verified 2026-10-07. Matching follows the OpenAPI response and media selection rules and RFC 9110 HTTP Semantics. Source versions inform this implementation; this toolkit is not affiliated with the OpenAPI Initiative.
Choose an explicit documented response instead · Compare two JSON Schema contracts