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WebSocket KingInsomnia
Free

Free to use in the browser.

 Freemium

Free to use, with a free account unlocking most features. Kong sells paid plans for teams…

Web Windows, macOS, Linux
  • Nothing to install
  • Focused on WebSocket testing and debugging
  • REST, GraphQL, gRPC, WebSockets and Server-Sent Events in one client
  • Local Vault and Git Sync mean the cloud is optional
  • WebSockets only, not a general HTTP client
  • Little public documentation about its features
  • Most features expect an account, even though a Scratch Pad works without one
  • The 2023 move to account-first storage cost it a lot of goodwill
Web application Downloadable app
Closed source Open source
License not stated License: Apache-2.0
Not stated if an account is needed No account needed
Not stated if it works offline Works offline

Checked September 24, 2026

Checked September 21, 2026

Catalog facts only. Anything “not stated” is unconfirmed. Check full listings for details.