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APIJuly 16, 2026·1 min read

How to test a REST API before you integrate it

By SyncBuilder

A REST API lets systems talk to each other over HTTP. Before you wire one into an integration, you want to confirm it actually responds the way the documentation says — the right status code, the right headers, and a body in the shape your workflow expects.

What to check

  • The HTTP status code (200 OK, 201 Created, 401 Unauthorized, 429 Too Many Requests…)
  • Response headers — content-type, caching, and any rate-limit hints
  • The body shape — are the fields you need present and correctly typed?
  • Authentication — API key, Bearer token or basic auth
  • Latency — how long the endpoint takes to respond

A quick manual test

Send a request with the method and URL, add any authentication headers, and inspect the raw response. Start with a GET against a read-only endpoint before you try anything that writes data, so a mistake can't change real records.

Never paste production secrets into tools you don't trust. Our REST API Tester proxies the request server-side (to get around the browser's CORS restrictions) and does not store your requests or credentials.

Give it a try: open the REST API Tester, paste an endpoint, and see the status, headers and body instantly.

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