Codeforces Stopwatch — Privacy Policy

Effective date: September 19, 2026

Codeforces Stopwatch records and analyzes your Codeforces practice on your device. It does not require an account, operate a backend, or send your practice data to the developer.

Information handled When you open the extension, it checks the active tab's URL. On a supported Codeforces problem page, it reads the visible problem title, rating, and tags. When you start practice, it saves the problem URL and identifier, those details, an attempt identifier, timestamps, Thinking/Coding changes, pauses, help usage, and the result you select. Imported backups may also contain legacy notes.

The extension uses this information to run the stopwatch, display your history, and calculate local statistics. It does not read submission source code, account credentials, cookies, other tabs, or your browser's history database. It does not monitor navigation in the background.

Storage and sharing Practice data is stored using Chrome's local extension storage in your Chrome profile. There is no cloud synchronization, advertising, tracking SDK, telemetry, or remote analytics service. The extension does not transmit this data to the developer or third parties, and does not sell it or use it for advertising or credit decisions.

All application scripts are included with the extension. Opening a problem link visits Codeforces normally; Codeforces handles that visit under its own policies. Chrome and the Chrome Web Store may separately handle installation and update information under Google's policies.

Your controls You can inspect your saved history in the popup and Analytics page, and export a JSON backup. Exported files remain wherever you save them and contain your practice history; sharing them is your choice. Import replaces existing history after confirmation. Completing another attempt for the same problem replaces its previous completed result. Older duplicate results are consolidated when loaded or imported.

Data remains in your Chrome profile until replaced, cleared through Chrome, or removed with the extension. You can remove individual tasks and their results from the History page after confirmation. To remove all extension data, uninstall the extension. Uninstalling does not delete JSON backups you exported; delete those files separately if desired.

Permissions - storage: save practice history locally. - activeTab: identify the current page when you open the extension. - scripting: read problem title, rating, and tags from that page after you invoke the extension.

No permanent host permission is requested.

Limited use and contact Use of data received through Chrome APIs is limited to providing the stopwatch, local history, and analytics features described here, consistent with the Chrome Web Store User Data Policy, including its Limited Use requirements.

For privacy or support questions, use the developer contact shown on the extension's Chrome Web Store listing. Changes to data handling will be described in an updated policy.