v1.0 is now available

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.

Open Source Local-first Git Sync Privacy first
Echolon Request Editor

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.

RESTWebSocketGraphQL (coming soon)

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:

BasicBearerAPI KeyDigestOAuth 2.0AWS v4JWT

Mocking

1-Click mocking for any API response with the a local OR cloud proxy.

LocalCloudBodyHeadersStatus
Features

Built for serious API work

See what makes Echolon the most powerful API client for developers.

Advanced Editor

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
Full request editor view
HTML Previews
Example Previews
Complete Request Editor
Dynamic Values

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
Variables view
Variables View
Version Control

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
Git integration panel with staged changes and commit dialog
API Docs

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
API publishing interface with sharing options
Development

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
Mock server configuration in Echolon
localhost:3001/api/users
Browser showing mocked API response
Features

Explore more

Discover all the powerful features that make Echolon the best API client.

Compare

How does Echolon compare?

See how Echolon stacks up against other popular API clients.

FeatureEcholonPostmanInsomniaBrunoHoppscotchScalarHTTPieYaakGetAPI
Open Source
PlatformsMac, Win, Linux, WebMac, Win, Linux, WebMac, Win, LinuxMac, Win, LinuxMac, Win, Linux, WebMac, Win, Linux, WebMac, Win, Linux, WebMac, Win, LinuxMac
REST
GraphQL
WebSocket
gRPC
MQTT
CollaborationGit-based and Cloud-basedCloud-basedCloud-basedGit-basedCloud-basedCloud-basedGit-basedCloud-based
Offline Mode
Free TierFree foreverLimitedLimitedFree foreverFree tierFree foreverLimitedFree tierFree tier
API Testing
Mocking Local
Mocking Cloud
Git Integration
No Vendor Lock
Scripting
Variables
1-Click Spec Publishing
Export to Code
PrivacyLocal-firstCloud syncCloud syncLocal-firstCloud optionalLocal-firstCloud syncLocal-firstCloud only
VC-FundedNo225M Series DAcquired by KongNo3M Series ANo6.5M Series BNoNo
Indie DevYesNoNoNoNoNoNoYesYes
Full support
Partial support
Not supported

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 macOSWindowsLinuxWeb