How the extension handles your data
The Beauty Diagram browser extension re-renders Mermaid and PlantUML diagrams in place on the pages you read. This policy explains exactly what it accesses, why, and what stays on your device.
Last updated June 25, 2026
What the extension accesses
The extension only reads the source text of the diagrams it renders — for example a Mermaid or PlantUML code block, or a diagram a supported site has already rendered. It does not read the rest of the page, your browsing history, your form inputs, or any unrelated content.
How that data is used
To turn a diagram into a polished image, the extension sends its source text to our rendering service at api.beauty-diagram.com and displays the image it returns. This happens only for diagrams that are actually rendered — automatically on the built-in supported sites, on any other site you switch on yourself, or when you click the Render button on a code block. The source is used solely to generate that image.
What is stored on your device
Your preferences, such as the default theme and width, are kept in the browser's synced extension storage. Per-site on and off choices and an optional Pro API key are kept in local extension storage only — the API key is never synced and is sent only to the rendering service as an authorization token to remove the watermark. Removing the extension clears all of it.
Site permissions
On a curated list of built-in sites — such as GitHub, GitLab, Jira and Confluence, dev.to, Stack Overflow, Linear, Hashnode, and the major AI chat tools — the extension runs automatically. On every other site it stays inactive until you turn it on from the toolbar popup, at which point your browser asks you to grant access to that specific site. You can revoke that access at any time.
What we do not do
The extension contains no analytics, tracking, or advertising. We do not sell or rent your data, build advertising profiles, or collect names, emails, or other personal information through the extension.
Sharing
Diagram source is processed by our own rendering service at api.beauty-diagram.com and the infrastructure providers that operate it on our behalf. We do not share it with anyone else except where required by law.
Your choices
You can turn the extension off for any site, disable it entirely, remove your API key, or uninstall it at any time. For questions or data-removal requests, contact us at service@beauty-diagram.com.
Contact
If you have questions about how the browser extension handles your data, contact us at service@beauty-diagram.com.