Top Open Source Browser Extensions Tools in 2026
A curated collection of the 19 best free and open-source Browser Extensions tools in 2026. Compare features, GitHub stars, tech stacks, and self-hosted software.
Waterfox
Privacy-focused open-source web browser
Stars6,202Last commit11d agoLicenseOpen Source
Skyvern
AI-powered browser automation for any website
Stars22,857Last commit12d agoLicenseAGPL-3.0Harper
Open source grammar checker that analyzes your writing quickly while keeping your data completely private and secure on your device.
Stars14,746Last commit12d agoLicenseApache-2.0Valour
Open-source community platform with chat, wikis, and voice
Stars393Last commit11d agoLicenseAGPL-3.0
Quiet
Peer-to-peer encrypted messaging without servers
Stars2,642Last commit13d agoLicenseGPL-3.0T3 Code
Open-source control plane for coding agents
Stars20,667Last commit10d agoLicenseMITSWE-agent
AI-powered autonomous software engineering agent
Stars20,151Last commit1mo agoLicenseMITScreenity
Privacy-friendly screen recorder & video editor
Stars18,509Last commit19d agoLicenseGPL-3.0
Requestly
Git-native API client for teams to design, build and test APIs
Stars6,750Last commit1mo agoLicenseOpen SourceLinguist
Privacy-first browser translator for Chrome & Firefox
Stars1,054Last commit16d agoLicenseBSD-3-Clause
LanguageTool
AI-powered grammar and style checker
Stars14,876Last commit10d agoLicenseLGPL-2.1
PeerTube
Decentralized free video platform alternative to YouTube
Stars15,277Last commit12d agoLicenseAGPL-3.0Emdash
Open-source agentic development environment
Stars5,509Last commit12d agoLicenseApache-2.0
Continue
Open-source coding agent for developers
Stars35,644Last commit1mo agoLicenseApache-2.0Cloudmark
Universal bookmark manager with one-click saves
Stars75Last commit27d agoLicenseAGPL-3.0
