How to test a REST API in Chrome

Install a REST client for Chrome

Install Pico API from the Chrome Web Store (or search “Pico API” in the store). Click the toolbar icon and the client opens in a normal browser tab — no sign-up, no workspace setup, and everything stays on your machine.

Enter the endpoint URL and method

Pick the HTTP method — GET, POST, PUT, PATCH, DELETE, HEAD, OPTIONS — and type the endpoint, e.g. https://api.example.com/v1/users. Query parameters go in the Params table and sync into the URL as you type.

Add headers, auth, and a body

Most APIs need an auth header. Use the built-in auth options (Bearer token, Basic, API key) instead of typing headers by hand. For requests with a body, pick a format:

• raw JSON — Content-Type is auto-detected and validated as you type
• x-www-form-urlencoded and multipart/form-data — key/value rows, including file upload
• XML / plain text

Send and inspect the response

Hit Send (or the ⌘/Ctrl+Enter shortcut). The response panel shows status, timing, size, headers, cookies, and a collapsible JSON tree with copy-path on every node. Streaming endpoints (SSE, chunked) render chunk by chunk as they arrive — handy for AI/LLM APIs.

Use environments for dev / staging / prod

Instead of editing the URL every time, define {{baseUrl}} once per environment and switch environments from the sidebar. The same request now targets whichever server you choose.

Automate checks with test scripts

Add a post-response script with Postman-style assertions:

pm.test('returns 200', () => pm.response.code === 200)
pm.test('user list is an array', () =>
  Array.isArray(pm.response.json()))

Pass/fail results appear in a Tests tab after every send, so regressions in your API show up immediately.

Bring your existing requests along

Paste a cURL command into Import and Pico API reconstructs the request — or try the online cURL converter first to see what will be parsed. OpenAPI/Swagger specs and ApiFox projects import as full collections.