Postman is well-designed and powerful for the work it’s designed for: managing collections of requests, switching between environments, testing across a team, running automated test suites. It’s also a desktop app that requires an account, syncs your data to the cloud, and takes a minute to get running.
For a quick test — “does this endpoint return what I expect?”, “does this auth header work?”, “what does this API actually return for this query?” — that’s overhead you don’t need.
Browser-based options
Hoppscotch is the most complete browser-based API client. It started as a lightweight Postman alternative and has grown significantly. REST, GraphQL, WebSocket, and MQTT support. Has workspaces, collections, environment variables, and team sharing. Open source and self-hostable. If you want Postman’s feature set without the desktop install requirement, Hoppscotch is the closest equivalent. The interface is fast and the keyboard shortcuts are well-thought-out.
Best for: teams that want Postman-style collections without the desktop install, projects where you want to save and organize requests, GraphQL testing.
ReqBin is simpler. Enter a URL, pick a method, add headers and a body, send. No collections, no environments, no saved history. Clean and fast for one-off requests. Server-side processing means it can bypass CORS restrictions that would block a browser-based client.
Best for: the most basic “just check if this URL responds” case.
DevBottle API Tester runs entirely in your browser. GET, POST, PUT, DELETE, PATCH, HEAD, OPTIONS. Add headers as key-value pairs, choose a body format (JSON, form data, URL-encoded), and send. The response panel shows status code, response time, headers, and a formatted body. Requests go straight from your browser to the API, and headers are never saved. Copy as cURL or fetch() when you want to run the same request elsewhere.
Best for: quick checks during development, testing a new API before writing integration code, verifying a webhook handler returns the right status, checking if an auth token works.
Chrome DevTools
DevTools has an underused feature: in the Network tab, right-click any request and select “Copy as fetch” or “Copy as cURL”. You get the exact request parameters — URL, method, headers, cookies. Paste into the Console to replay it, or paste the cURL into a terminal. You can also edit the fetch call before running it.
This is often the fastest way to re-test a request you already triggered from the browser. No separate tool to open, and you know the exact headers and cookies your browser sent.
Best for: replaying or modifying requests you’ve already made in the browser, checking exactly what headers your frontend sends.
When CORS gets in the way
Browser-based tools are subject to CORS restrictions. If the API you’re testing only allows requests from certain origins, the browser will block the response even though the request went out successfully. You’ll often see this as an empty response body with a network error in the console.
ReqBin routes requests through their server, which sidesteps CORS entirely. Hoppscotch has a CORS proxy option. Browser-only tools like DevBottle’s API Tester will be blocked by restrictive CORS policies.
For APIs with strict CORS, a desktop client (Postman, Insomnia, Bruno) or cURL in a terminal are more reliable — they don’t go through the browser’s CORS model. For what triggers a preflight request, how to recognize a CORS failure, and a full routine for testing an endpoint, see How to Test a REST API Endpoint.
When to use Postman (or Insomnia or Bruno)
For work where you’ll be hitting the same endpoints repeatedly, working with a team, or running automated API test suites, a desktop client earns its weight. Collections, environment variables, and test scripts save real time when you’re deep in API development.
But for a quick check, the overhead isn’t worth it. Open a tab, test the endpoint, close the tab.
Test API endpoints in the browser. Supports all HTTP methods, custom headers, and JSON bodies.
