Privacy Policy — Dual Preview

Last updated: June 2026

Dual Preview is a Chrome extension that displays websites in mobile and desktop view side by side. This policy describes what data the extension accesses and how it is used.

Data we collect

The extension reads browsing history solely to provide URL autocomplete suggestions in the address bar. This data is never stored, transmitted, or shared.

Data stored locally

The following preferences are saved in chrome.storage.local on your device only and are never sent anywhere:

• Selected background color or image
• Custom background images uploaded by the user
• Scaling mode preference
• Panel size settings
• Audio mute preference

Permissions used

• cookies — removes deployment-pinning cookies for the extension's own new-tab page to ensure it always loads the latest version.
• declarativeNetRequest / declarativeNetRequestWithHostAccess — modifies the User-Agent request header to enable mobile or desktop browser emulation.
• history — provides URL suggestions in the address bar. Data is read locally and never transmitted.
• scripting — injects a script to override User-Agent strings in the page's JavaScript context for accurate emulation.
• storage / unlimitedStorage — stores user preferences and custom background images locally on your device.
• tabs — opens the extension panel in a new tab when the toolbar icon is clicked.

Analytics

The extension uses PostHog to collect anonymous usage analytics (e.g. which features are used, how often the extension is opened). No personally identifiable information is collected.

PostHog — EU cloud infrastructure

All analytics data is processed exclusively on PostHog's EU cloud servers (hosted in the European Union), in compliance with GDPR. No data is transferred outside the EU.

We do not know which websites you visit

Dual Preview loads websites inside browser frames (iframes). Due to browser security restrictions, the extension has no access to the content or addresses of websites displayed inside those frames. We do not collect, store, or transmit any URLs of pages you browse using the extension. We genuinely do not know which websites our users visit — this information is technically inaccessible to us.

You can opt out of analytics at any time by contacting us.

Data sharing

Dual Preview does not sell or transfer any user data to third parties. Anonymous analytics data is processed by PostHog solely for product improvement purposes.

Contact

Questions? Email: tokamil100@gmail.com