How Sealvane works
What is a lookup?
Before your phone or laptop can open a website, it has to ask where that website lives. It sends a short question, something like “where is example.com?”, and gets an answer back. That question is a DNS lookup. Every site, app and link triggers one, usually many times a minute. Your device normally asks whoever runs your Wi-Fi or mobile network. With Sealvane, it asks Sealvane instead.
What gets blocked
Sealvane checks each lookup before it is answered. We block:
- scam and phishing sites, such as fake bank or delivery pages;
- malware sites;
- lookups that carry card numbers or ID numbers out of the device. Some harmful software hides stolen data inside the website names it asks for, and that is what we look for.
No filter is perfect. Some bad sites will get through, and now and then a harmless site may be blocked by mistake. Sealvane is an extra layer, not a replacement for antivirus or for care with links and messages.
What happens when something is blocked
Instead of the dangerous page, you see a simple block page. It says that Sealvane stopped the site and gives the reason, for example that it is a known scam or phishing site. The page never loads, so nothing from it reaches your device.
See it block a scam
Pick a link, as if it had landed in a message. The phone shows what happens when your device looks it up.
Example - no real sites are visited
What we see, and what we don't
What we see
- The website name your device asked for, and when.
- What we did with it: allowed or blocked, and why.
- Your device by its label, such as “Mum’s phone”. Computer addresses are kept only as keyed hashes.
- Card and ID numbers, if found, shown masked.
What we don't see
- The pages you read or what you type on them.
- Your emails, messages or files.
- Your passwords.
- Anything on a device that is not using your Sealvane address.
Lookup records are deleted automatically after 90 days. Dashboards show devices as labels, not browsing histories tied to people. We do not sell your information. The full detail is in the privacy policy.
If Sealvane can't be reached
Sealvane works by answering your device's lookups, so your device needs to be able to reach it. On Android, if Private DNS is set to a hostname and your device cannot reach the server, lookups stop: your device shows a connection error until it can reach Sealvane again. Switching Private DNS back to Automatic restores normal internet straight away. Other devices can behave a little differently, and our setup guides explain how to switch Sealvane off on each one.
Today our servers are in South Africa only. We do not promise a particular level of uptime, and we will tell you plainly if that changes.
Where it works
Because the protection is set on the device itself, it works on any network: home Wi-Fi, mobile data, hotel Wi-Fi, abroad. Offices can also point their router at Sealvane with one setting, to protect every device in the building.