RenderDiff Privacy Policy

RenderDiff is a browser extension that compares the initial HTML of any webpage with its JavaScript-rendered DOM to identify SEO-relevant differences. All processing happens locally in your browser.

What data is collected

None. RenderDiff does not collect, transmit, or store any personal data, browsing activity, scan results, or telemetry. The Firefox manifest formally declares data_collection_permissions with required set to "none" to signal this to Mozilla.

What data is stored locally

A single preference: your optional Custom User-Agent string, persisted via the browser's storage.local API only when you choose the "Custom" preset and enter a value. Nothing else is stored. The preference never leaves your device.

What network requests RenderDiff makes

Exactly one outbound HTTP request per scan: a fetch of the URL you explicitly choose to scan, performed when you click the toolbar icon. The response is processed locally and never uploaded anywhere. RenderDiff makes no requests to its developer, to any analytics service, or to any third party.

Permissions explained

• activeTab and scripting: read the rendered DOM of the active tab, only on explicit user action.
• storage: persist the optional Custom User-Agent string locally.
• clipboardWrite and downloads: power the export buttons (Copy, JSON, CSV, PDF).
• declarativeNetRequestWithHostAccess: apply a session-scoped User-Agent header override on the active tab so you can rescan the page as Googlebot or another crawler. Removed automatically when the tab closes.
• host_permissions set to all URLs: required because the extension is a universal SEO tool that must work on any URL the user opens.

No accounts, no tracking

RenderDiff has no user accounts, no login, no tracking, no analytics, no cookies, no third-party SDKs, and no remote configuration.

Contact

For privacy questions, contact renderdiff@timberlin.de.

The full privacy policy of the publisher, covering the website itself, is available at https://timberlin.de/privacy/.