Free Postman Alternatives in Your Browser — API Tools Without Installation

Postman is powerful but it's also heavy, increasingly requiring accounts and cloud sync, and the free tier has gotten more limited over time. If you need to test APIs without installing anything or creating an account, browser-based alternatives are worth knowing.

Hoppscotch (formerly Postwoman)

Hoppscotch is the best direct Postman alternative in a browser. It's open source, runs entirely client-side, and supports REST, GraphQL, and WebSocket. You can use it at hoppscotch.io or self-host it. No account required for basic use.

The browser DevTools approach

For testing APIs your frontend app calls, DevTools is already perfect. Open the Network tab, make the request in your app, right-click the request, and select "Copy as cURL". Then modify and replay that curl command in the terminal. No extra tool needed.

# Paste the copied cURL command and modify as needed
curl 'https://api.example.com/users'   -H 'Authorization: Bearer eyJ...'   -H 'Content-Type: application/json'   --data-raw '{"name":"Alice"}'

curl + jq: the terminal stack

For developers comfortable in the terminal, curl and jq together beat GUI tools for scripting and automation:

# Pretty-print response
curl -s https://api.example.com/users | jq .

# Extract a field
curl -s https://api.example.com/users/1 | jq .email

# POST and extract from response
curl -s -X POST https://api.example.com/users   -H "Content-Type: application/json"   -d '{"name":"Alice"}' | jq .id

Thunder Client (VS Code extension)

If you're already in VS Code, Thunder Client is a lightweight REST client extension that works directly in the editor. No browser tab switching, works offline, stores requests locally. Free for basic use.

Inspecting formatted API responses

Whatever tool you use to make the request, formatted JSON is easier to inspect. After fetching a response, paste it into our JSON Formatter to quickly scan the structure and spot issues.