Best API Clients in 2025

The Collaboration Platform for API Development.

Key Postman features:

User-Friendly Interface Collaboration Comprehensive Testing Tools Extensive API Documentation

Open Source

Bruno is a Git-integrated, fully offline, and open-source API client.

Key Bruno features:

User-Friendly Interface Comprehensive Feature Set Regular Updates Strong Customer Support

A Powerful API Mocking and Testing Tool.

Key Requestly features:

Redirect URL Block Network Requests Modify Request & Response Header Modify Response

Open Source freemium

HTTP proxy / HTTP monitor / Reverse Proxy.

Key Charles Proxy features:

Comprehensive HTTP/HTTPS Debugging User-Friendly Interface Support for Various Platforms Throttling Feature

Fiddler is a debugging program for websites.

Key Fiddler features:

Comprehensive Debugging Cross-Platform Compatibility Custom Scripting User-Friendly Interface

Beautiful, cross-platform & open-source tools to debug, test & build with HTTP(S). One-click setup for browsers, servers, Android, CLI tools, scripts and more.

Key HTTP Toolkit features:

Ease of Use Cross-Platform Compatibility Open Source Comprehensive Debugging Features

Open Source freemium €7.0 / Monthly (for a Pro subscription)

The best place to backorder/drop purchase expiring ccTLD domain names.

Key Replay.io features:

Ease of Use Debugging Capabilities Collaboration Cross-Browser Support

Open Source

Proxyman is a high-performance macOS app, which enables developers to view HTTP/HTTPS requests from apps and domains.

Key Proxyman.io features:

User-Friendly Interface Cross-Platform Support Real-time Traffic Interception HTTPS Decryption

Open Source $49.0 / Annually

Saw a bug? Send an instant replay to engineers. It will come with console logs and everything. Developers will ❤️ you.

Key Bird Eats Bug features:

Ease of Use Comprehensive Bug Reports Time-Saving Integration Capabilities

Open source API development ecosystem.

Key Hoppscotch features:

User-Friendly Interface Open Source Multi-Platform Support Real-Time Collaboration

Open Source freemium

Wireshark is a network protocol analyzer for Unix and Windows. It lets you capture and interactively browse the traffic running on a computer network.

Key Wireshark features:

Comprehensive Protocol Support Free and Open-Source Cross-Platform Compatibility Rich Feature Set

Open Source

Design, debug, test, and mock APIs locally, on Git, or cloud. Build better APIs collaboratively for the most popular protocols with a dev‑friendly UI, built-in automation, and an extensible plugin ecosystem.

Key Insomnia REST features:

User-Friendly Interface Support for Multiple Protocols Environment Management Custom Plugins and Themes

Open Source

Edit your website right from the page, and easily send the exact change to engineers to copy/paste.

Key Jam Edit features:

User-Friendly Interface Collaboration Features Customizable Templates Integration Capabilities