Craft canned API responses with status codes, headers, and bodies for testing error paths. Simulate 404s and 500s without a server — local, free, no signup.
Content reviewed October 2026 · About Toolzum
Send HTTP requests from your browser — custom headers, bodies, params, saved collections, and one-click cURL/Fetch/Axios snippets. Developers debug a REST endpoint without leaving the tab — runs locally, free to start.
Build HTTP requests with method, URL, headers, and body — then generate matching curl commands. Prototype endpoints without leaving the tab — local, free, no signup.
Test any HTTP endpoint by sending GET, POST, PUT, or DELETE requests directly from your browser. View response status, headers, and body.
Encode images to Base64 data URIs for CSS embedding and API payloads. Inline a logo without extra requests — local encoding, free, no signup.
Renders a scannable QR code from any text or URL with a client-side Reed-Solomon encoder at fixed high error correction. Customize size, colors, and center logo, then download the PNG — free, local, no signup.
Generate 404, 429, and 500 responses with realistic bodies: point your client at the mock shape and verify retries, toasts, and fallbacks trigger correctly.
Yes — rate-limit headers (X-RateLimit-Remaining), pagination links, and content types generate alongside bodies for faithful client tests.
Mocks cover shape and status handling fast; run live integration before release for auth, latency, and real error text. Both layers, in that order.
No — generation runs locally in your browser. Nothing leaves your device.
API Mock Data Generator
Generate realistic mock JSON from field specs — names, emails, dates, nested objects. Fill frontends before backends exist — local generation, free, no signup.
OpenAPI Mock Generator
Generate mock endpoints from OpenAPI specs — example responses shaped for immediate frontend work, no backend wait while real backends are still being built.