Privacy Policy

Last updated: March 2026

What we collect

Very little. When you use IsUp to check a website, our server makes an outbound HTTP request to that website on your behalf. We do not log the URLs you check, and we do not store your results on our server.

Server logs

Our web server (Nginx) keeps standard access and error logs as part of normal operation. These may include your IP address, browser user-agent string, the page you visited, and the time of the request.

Cookies & sessions

IsUp uses a PHP session cookie to enforce rate limiting (preventing abuse of the checker). This cookie contains only a random session identifier.

Local storage

Your recent checks are saved in your browser’s localStorage so you can see them when you come back. You can clear it at any time through your browser settings.

Data security

All connections to IsUp are encrypted via HTTPS. The checker endpoint blocks requests to private and internal networks (SSRF protection).

Contact

If you have questions, contact us at modularwebsystems@gmail.com.

Changes

If we change this policy, we’ll update the date at the top. Material changes will be noted on the homepage.