The API client for
devs
A powerful, local-first API client with Git integration, offline support, and multi-protocol capabilities. Open source alternative to Postman.
Everything you need
Echolon keeps things simple by default, exposing features only when needed.
Open Source
Echolon is open source and free to use.
Local-first / Zero Logins
All your data is saved locally and does not force to signup for any account in the cloud.
Call any API
Mix multiple protocols together and work on any API within a single workspace.
Git Sync
Fully git-native. All workspaces, collections, variables and settings are stored in your local file system.
Authenticate anything
Automatically handle complex request authentication, so you don't have to:
Mocking
1-Click mocking for any API response with the a local OR cloud proxy.
Built for serious API work
See what makes Echolon the most powerful API client for developers.
Advanced Request Editor
Powerful request editing with rich content type previews, JSON-Path filtering, and live schema validation. See your API responses beautifully rendered.
- Multiple content type previews (JSON, XML, HTML, images)
- JSON-Path filtering for quick data extraction
- Live schema validation against OpenAPI specs
- Example previews from your API documentation
Powerful Variable System
Define variables in headers, query parameters, body or scripts. Use built-in dynamic functions to generate timestamps, UUIDs, random data, and more.
- Variable tooltips showing value origin & scope
- Define at global, workspace, or collection level
- Rich built-in functions ($timestamp, $uuid, $random)
- JavaScript expression support for complex logic
Built-in Git Integration
Full Git integration with a visual interface. Stage changes, commit, push, and pull without leaving Echolon. Your API collections are always version-controlled.
- Visual diff viewer for changes
- Stage and commit changes inline
- Branch management and switching
- GitHub integration
One-Click API Publishing
Publish your API documentation to the web with a single click. Share beautiful, interactive API references with your team or the world.
- Set up route in seconds
- Enable sharing with one click
- Publish instantly to the web
- Beautiful, interactive documentation
Powerful API Mocking
Create mock servers instantly. Test your frontend without waiting for the backend. See requests in real-time and customize responses on the fly.
- Local and cloud mock servers
- Real-time request monitoring
- Custom response bodies, headers, and delays
- Status code simulation for error handling
Response Size Breakdown
See exactly how much bandwidth each response uses. Compare uncompressed size with gzip, brotli, and zstd. Use the savings calculator to estimate total transfer at any request rate and duration.
- Body size by encoding (uncompressed, gzip, brotli, zstd)
- Compression time in milliseconds
- Savings calculator: requests per unit + duration
- Total bandwidth estimate with locale-formatted numbers
Light or Dark
Choose your preferred theme. Switch seamlessly between light and dark mode to match your workflow.
Explore more
Discover all the powerful features that make Echolon the best API client.
How does Echolon compare?
See how Echolon stacks up against other popular API clients.
| Feature | Echolon | Postman | Insomnia | Bruno | Hoppscotch | Scalar | HTTPie | Yaak | GetAPI |
|---|---|---|---|---|---|---|---|---|---|
| Open Source | |||||||||
| Platforms | Mac, Win, Linux, Web | Mac, Win, Linux, Web | Mac, Win, Linux | Mac, Win, Linux | Mac, Win, Linux, Web | Mac, Win, Linux, Web | Mac, Win, Linux, Web | Mac, Win, Linux | Mac |
| REST | |||||||||
| GraphQL | |||||||||
| WebSocket | |||||||||
| gRPC | |||||||||
| MQTT | |||||||||
| Collaboration | Git-based and Cloud-based | Cloud-based | Cloud-based | Git-based | Cloud-based | Cloud-based | Git-based | Cloud-based | |
| Offline Mode | |||||||||
| Free Tier | Free forever | Limited | Limited | Free forever | Free tier | Free forever | Limited | Free tier | Free tier |
| API Testing | |||||||||
| Mocking Local | |||||||||
| Mocking Cloud | |||||||||
| Git Integration | |||||||||
| No Vendor Lock | |||||||||
| Scripting | |||||||||
| Variables | |||||||||
| 1-Click Spec Publishing | |||||||||
| Export to Code | |||||||||
| Privacy | Local-first | Cloud sync | Cloud sync | Local-first | Cloud optional | Local-first | Cloud sync | Local-first | Cloud only |
| VC-Funded | No | 225M Series D | Acquired by Kong | No | 3M Series A | No | 6.5M Series B | No | No |
| Indie Dev | Yes | No | No | No | No | No | No | Yes | Yes |
Frequently asked questions
Everything you need to know about Echolon.
Yes! Echolon is completely free and open source for personal use. We offer optional paid features for teams and enterprise users who need advanced collaboration features, but the core API client functionality is free forever.
Echolon is a lightweight, local-first alternative to Postman. Unlike Postman, Echolon stores all your data locally as plain text files that work with Git. There's no mandatory cloud sync, no account required, and no subscription needed for basic features.
Absolutely! Echolon supports one-click import from Postman, Insomnia, Bruno, OpenAPI/Swagger specs, and even cURL commands. Your existing workflows can be migrated in minutes.
Yes, Echolon is built with an offline-first architecture. All your collections, environments, and settings are stored locally on your machine.
Echolon supports REST/HTTP, WebSocket. GraphQL support is on the roadmap
Your data never leaves your machine unless you explicitly choose to sync it via Git. We don't collect telemetry, track usage, or require you to create an account. Sensitive values can be encrypted at rest. There is an opt-in to track basic usage statistics (off by default of course).
Yes! Teams can collaborate by storing collections in a shared Git repository. Changes are merged through standard Git workflows. Optionally, you can use the public API collection sharing to showcase your APIs to the world.
You can open issues on GitHub for bug reports and feature requests or check out our documentation for guides and tutorials. You can also get support at support@echolon.app
Ready to try Echolon?
Join thousands of developers building better APIs. Free forever for personal use.
Available for macOS • Windows • Linux • Web