CookieCloud is a browser extension that synchronizes cookies and local storage between browsers and a self-hosted server with end-to-end encryption.
The tool addresses the need to maintain consistent authentication state and local data across devices and browsers. It works by running a browser extension that periodically uploads cookies and local storage to a server you control, then allows other browsers to download and apply that data. The synchronization is one-way per browser instance—one browser uploads while others download—and includes built-in end-to-end encryption to protect sensitive data in transit. Users can configure the synchronization interval to suit their needs.
CookieCloud suits developers and privacy-conscious users who want to share session data across devices without relying on cloud services or browser sync features. It works best for those willing to self-host a server and manage their own infrastructure. The tool officially supports Chrome and Edge; Firefox is possible but requires manual compilation from source code, and cookie format differences between browsers mean Firefox and Chrome cookies cannot be mixed. The project includes both the browser extension source code and the server-side implementation, giving adopters full control over their data.
Development activity shows consistent maintenance with regular updates addressing user feedback. The project underwent a significant rewrite using the wxt framework to support improved encryption standards and broader browser compatibility. Breaking changes were introduced to add local storage synchronization alongside cookies, requiring users to reconfigure their setups. The maintainers actively engage with the community through official channels and provide documentation including video tutorials and written guides.
