Privacy: your files never leave your browser

formatdesk is a static website. There is no server-side code that receives, stores or processes your files. Every tool runs as JavaScript (and, for some formats, WebAssembly) inside your browser tab.

What happens when you open a file

• The file is read with the browser's File API directly from your disk into the memory of the current tab.
• Parsing and conversion run in the page or in a Web Worker on your device. Nothing is sent over the network.
• Downloads are created locally as in-memory blobs; the temporary blob URL is revoked right after the download starts.
• Closing the tab discards the data. We do not keep your content in cookies, localStorage or any other storage.

Previews of untrusted HTML

HTML previews are rendered inside an <iframe sandbox="allow-scripts"> without allow-same-origin. The preview runs in a unique, opaque origin, so code inside it cannot read this site, your cookies or storage, cannot navigate this page and cannot submit forms. In Safe mode scripts are also removed with DOMPurify and blocked by a Content Security Policy.

If the page you preview references external images, fonts or stylesheets (for example from a CDN), your browser will request them from those servers, just like when opening the file locally. With scripts turned on, external script files (https only) are loaded the same way and run inside the same sandbox. The viewer warns you about such resources and offers a switch to block them.

Opening files by URL

When you use "Open from URL" and click Load, your browser downloads the file directly from the https address you entered. The request does not go through our servers, carries no cookies and no referrer; the server you named sees your IP address, as with any download. A link to a tool with ?url= only fills in the address field – nothing is downloaded until you click Load. The address is never sent to analytics.

Analytics

We plan to use privacy-friendly, cookie-less analytics that count events such as "a file was opened" with a coarse size range (for example "under 1 MB"). File names, URLs and contents are never part of any event. No analytics provider is active at the moment.

Advertising

Pages may show advertising in the future. Ad scripts would never receive your files: they would run outside the tool area, and the tool never shares data with them. This page will be updated before any ad network is enabled.

Settings stored on your device

The only thing stored is your light/dark theme choice (in localStorage), if you change it.

Contact

Questions about privacy, a bug report or a feature request:contact@formatdesk.dev.