Privacy Policy

Last updated: May 12, 2026

Mermaid Preview is a browser-based Mermaid diagram editor. This policy explains what information may be processed when you use the editor, examples, tutorials, and other pages on this website.

The Mermaid source code you type into the editor is rendered in your browser. Mermaid Preview does not upload your diagram text to an application server for rendering. If you use the share feature, the diagram text is compressed into the URL fragment after the # symbol. URL fragments are normally handled by the browser and are not sent as part of standard HTTP requests to our server.

We may collect limited technical and usage information to understand site reliability and improve the product. This may include page views, browser type, approximate device information, referrer information, time of visit, and non-personal interaction events. We do not ask visitors to create an account and we do not intentionally collect names, passwords, payment details, or private diagram content.

This site uses Umami Analytics for privacy-conscious traffic measurement. Analytics data helps us understand which pages are useful, which tutorials need improvement, and whether the editor is working across common browsers.

Mermaid Preview may load third-party resources such as Google Fonts, CodeMirror assets, Mermaid rendering libraries, analytics scripts, and advertising scripts. These providers may receive technical information such as your IP address, browser details, and the page URL needed to deliver their resources.

This site uses Google AdSense to display advertisements. Google may use cookies and similar technologies to serve, measure, and personalize ads based on your visits to this and other websites. To learn more about how Google uses data, visit Google's advertising policies.

You can control cookies through your browser settings. You can also learn about interest-based advertising choices through resources such as Network Advertising Initiative and Google's ad settings.

We retain analytics and operational information only for as long as it is useful for understanding site performance, security, and product quality. If you contact us by email, we will use your email address and message only to respond to your request.

If you have privacy questions or want to report a concern, contact contact@mermaidpreview.com. See also our Terms of Service and About page.