Scalar vs Voiden

Comparing two open source alternatives to Postman and Thunder Client and Paw and Apidog. Use the comparison below to decide which one fits your needs.

Scalar

MIT

Scalar is an open-source API platform:　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　🌐 Modern Rest API Client　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　📖 Beautiful API References　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　✨ 1st-Class OpenAPI/Swagger Support

Visit Full details

Voiden

Apache-2.0

Design, test and document APIs in plain Markdown with a git-native, offline-first approach.

Visit Full details

Side-by-side comparison

	Scalar	Voiden
License	MIT	Apache-2.0
Self-hostable	No	No
GitHub Stars	16,249	1,767
Forks	946	86
Open Issues	42	20
Last Commit	Oct 10, 2026	Oct 9, 2026
First Released	Aug 16, 2023	May 9, 2025
Categories	API Development & Testing Tools	API Development & Testing Tools
Tags	#API #api client #rest #http client	#API #api client #DeepSeek #cli #markdown

GitHub stars over time

Scalar16,249

Voiden

Similar open source alternatives

Hoppscotch

Open source API development ecosystem - https://hoppscotch.io (open-source alternative to Postman, Insomnia)

Alternative to:

Postman

HTTPie

Open-source command-line and desktop HTTP client with intuitive syntax, JSON support, and built-in auth — a developer-friendly Postman alternative.

Alternative to:

Postman

Bruno

Opensource IDE For Exploring and Testing API's (lightweight alternative to Postman/Insomnia)

Alternative to:

Postman

Hurl

Run and test HTTP requests with plain text — a simple yet powerful command-line tool for API testing.

Alternative to:

Postman

Insomnia

The open-source, cross-platform API client for GraphQL, REST, WebSockets, SSE and gRPC. With Cloud, Local and Git storage.

Alternative to:

Postman

Yaak

The most intuitive desktop API client. Organize and execute REST, GraphQL, WebSockets, Server Sent Events, and gRPC 🦬

Alternative to:

Postman