API Tester (Web)
High-performance local-first HTTP REST API testing tool. Features VS Code tabbed workspace, {{baseUrl}} environment variables, body formatting, and 100% offline IndexedDB storage.
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Key Features
Local-First & 100% Offline
Stores all collections, environment variables, and history securely in browser IndexedDB without cloud sync or accounts.
VS Code Style Tabbed Workspace
Work on multiple requests simultaneously in tabs with fast keyboard shortcuts (Ctrl+Enter to send, Ctrl+K for command palette).
Environment Variables & Tree View
Supports dynamic {{baseUrl}} and {{token}} placeholders, with interactive collapsible JSON response tree viewer.
How to Use API Tester
- Enter the target URL and select the HTTP method (GET, POST, PUT, DELETE, etc.).
- Configure Query Params, Headers, Authorization (Bearer/Basic/API Key), or Body payload.
- Define environment variables like {{baseUrl}} to easily switch between servers.
- Click Send or press Ctrl+Enter to execute the HTTP request and view the response.
Frequently Asked Questions (FAQs)
Is my API key or request payload uploaded to any server?
No. All API requests, credentials, and local collections are stored 100% offline in your browser's IndexedDB.
How to handle CORS errors during testing?
Since requests originate from your browser client, the target API endpoint must allow Cross-Origin Resource Sharing (CORS headers).