API Tester — HTTP Client

A focused mobile HTTP client for Android. Compose GET / POST / PUT / PATCH / DELETE requests on the go, save them into collections, and read responses in a clean JSON tree — without opening your laptop.

API Tester is built for backend engineers, mobile developers, QA testers, freelancers in client meetings, and anyone who needs to ping an API from their phone. It's a Postman-lite for mobile — every feature you reach for in the desktop tool, distilled into a thumb-friendly dark-mode app.

WHAT YOU CAN DO

• Compose any HTTP request — method, URL, headers, body (JSON / form-data / raw), and authentication (No Auth / Bearer Token / Basic Auth / API Key) all on one screen.
• Save endpoints into collections with one tap. Organise them into folders, mark favourites, jump to any saved request fast.
• Switch environments — dev / staging / prod — with one segmented tap. Use {{variable}} tokens in URLs, headers, and bodies and they resolve from the active environment.
• Inspect responses in a real JSON tree — collapsible, syntax-highlighted, with status badge, time, payload size, and full response headers. Switch to raw mode any time.
• Browse a full history of every request you've sent — tap any row to re-open it in the composer.
• Free tier covers everything you need for ad-hoc API checks: 5 saved requests, all HTTP methods, full response inspector, JSON tree, environments, and history.

DESIGNED FOR FOCUS

• Dark theme tuned for long debugging sessions. Geist-style typography (Inter + JetBrains Mono).
• Method colours match the Postman / Insomnia palette you already know — desaturated for dark mode.
• Bottom-sheet pickers for method, URL, body, env, history — fast and keyboard-aware.
• Onboarding tour, contextual hints, swipe to dismiss everywhere.

PRIVACY-FIRST

API Tester is fully offline by default. Your requests, collections, environment variables, and tokens never leave your device — there is no account, no cloud sync, no telemetry. The only network calls the app makes are the ones you explicitly trigger with Send. The Pro upgrade unlocks OAuth, scripts, unlimited collections, WebSockets, and removes the single banner ad — your data stays yours either way. Read the privacy notice before you install: it's short and honest.

UPGRADE WHEN YOU NEED IT

The free tier is fully functional for ad-hoc testing. The optional Pro one-time purchase unlocks:

• Unlimited saved collections and folders
• OAuth 2.0 (Authorisation Code + PKCE and Client Credentials flows, custom-tab handler)
• Pre-request scripts (small JS sandbox — sign payloads, generate nonces, set timestamps)
• Response history per endpoint
• Postman v2 collection JSON import / export
• WebSocket request type
• Removes ads

Buy it once, keep it forever — no subscription.

Recent changes:
API Tester 2.0 — a full rewrite.
• WebSocket client with live frame log
• Collection runner with no-code tests & extractions
• Endpoint monitors with down/recovered alerts
• OAuth 2.0 (auth-code + PKCE, client credentials)
• Environments, cURL import, Postman import/export
• Faster, cleaner UI with light/dark themes