Lock Your Browser
to Only Trusted Websites

When Lockdown Mode is active, every website navigation is blocked by default. Only domains you have added to your Trusted Domains list are allowed through. Any attempt to visit a non-trusted website is immediately redirected to a warning page that shows the blocked URL and the reason it was blocked. File downloads are also blocked unless the file type is listed in your Trusted File Types.

Yes. Adding a domain like google.com automatically allows all of its subdomains, including for example accounts.google.com, mail.google.com, drive.google.com, and any others. This means you only need to add the root domain once to cover the entire service. If you want to restrict access to only one specific subdomain, add that subdomain directly instead of the root domain.

Yes. On the warning page shown when a website is blocked, there are two bypass options: "Add to trusted & open" which permanently adds the domain to your trusted list and navigates you there, and "Proceed anyway" which allows you to visit the page for that session only without saving it to your list. Both buttons can be hidden via the Settings tab to prevent bypassing blocks on managed devices.

In the Enterprise tab of the settings, you can enter an HTTPS URL pointing to a plain text file with one domain per line. The extension will automatically fetch that file at your chosen interval (every 15 minutes, hourly, every 6 hours, or daily) and replace the local trusted domains list with the remote one. This allows an administrator to control the trusted list for all browsers in an organization simply by editing one remote file. The same mechanism is available for trusted file types.

Yes. In the Authentication Headers section of the Enterprise tab, you can configure a custom HTTP request header name and value, for example, X-Access-Key with a secret token. This header is sent with every fetch request (HTTP GET), allowing your server to verify that the request is coming from an authorized browser and reject any other unauthorized access to the list.

No. All blocking logic runs entirely inside your browser. No URLs you visit, no blocked URLs, and no personal data are ever sent anywhere. The only outbound connections the extension makes are the optional Enterprise remote list fetches that you configure yourself, which go to the HTTPS URL you provide.

Yes. The Customize tab in the settings lets you replace the default APIVoid extension logo on the warning page with your own. You can provide a custom image URL with an optional width, or display a custom text string such as your company name. This is useful for organizations that want the blocked page to reflect their own branding rather than the default appearance.

Enable Lockdown Mode from the extension settings and then add the websites you want to allow to your Trusted Domains list. Once Lockdown Mode is active, every website that is not on your list is automatically blocked and redirected to a warning page. Adding a domain like google.com also allows all its subdomains such as mail.google.com and drive.google.com, so you only need to add the root domain once. You can add domains one by one, import a plain text file with one domain per line, or use the Enterprise remote list feature to manage the allowed list centrally across multiple browsers.

Yes. The Settings tab includes a Backup & Restore section where you can export all your settings — including trusted domains, trusted file types, enterprise sync URLs, and customization options — to a single JSON file. You can import this file on any other browser (such as a Firefox or Chrome browser) to instantly replicate your configuration. If the backup includes enterprise remote URLs, the extension will automatically fetch and apply those lists immediately after import and then at your specified interval.