Alertoscan Shield

Get warned before you land on a known scam or phishing site, checked privately on your device. For Chrome & Edge.

Free · No account · Open source · Rolling out to the Web Store & Edge Add-ons

How it works

Privacy-first by design. The check happens on your device, not on our servers.

It downloads a compact, cryptographically signed list of flagged domains and verifies it before use. A tampered or older list is rejected.

Every site you visit is tested against that list locally. Around 99% of browsing matches nothing and never touches the network.

Only when a domain matches does it ask alertoscan.io for that one site's verdict: trust score, category and why it's flagged.

Default

Click the toolbar icon to check the site you're on. Nothing runs in the background.

Opt-in

Flagged sites automatically show an in-page banner and a toolbar badge as you browse.

Opt-in

Flagged sites are replaced by a full-page warning before you can interact with them.

The blocklist is downloaded and every site is checked locally. About 99% of your browsing never leaves your device.

No sign-up, no analytics, no profiles. Only a matched site triggers a single lookup for that one domain.

The blocklist is cryptographically signed and verified before use. A tampered or rolled-back list is rejected.

The only server the extension ever talks to is alertoscan.io. Nothing else.

Minimal by default. Anything that can see your pages is strictly opt-in.

activeTabCheck the current site when you click the icon.

storageKeep the blocklist and your settings on the device.

alarmsRefresh the blocklist once a day.

scriptingShow the in-page warning banner (active protection).

host access (optional)Requested at runtime only if you enable active protection or block mode. Revocable anytime.

Free, no account, and open source. Add it to your browser and get a heads-up before a scam site can reach you.