Security

Sveltiq compresses documents entirely in your browser. There is no mechanism that sends your files to a server. This page explains the technical basis and how you can verify it yourself.

1. How your data is handled

Files you drop are processed in your device's memory using standard browser JavaScript. File data is never sent to any external server during processing. Once you finish downloading, the in-memory data is released. We do not collect or record file names, sizes or any other metadata.

2. Communication with external services

This site makes no requests to third-party services. There are no ads, no external analytics and no external fonts; everything the page needs (HTML, scripts, fonts, images) is served from this site itself.

The only exception is when you submit the contact / bug-report form yourself: its contents and diagnostic details go to our hosting platform (Cloudflare). That is completely separate from file processing.

There is also an optional donation link to an external service (Ko-fi). No communication happens unless you click it, and we never receive your payment details.

3. How processing works

• Text, tables and layout stay intact — only the file gets lighter.
• The original format (PowerPoint / Word / Excel / PDF) is preserved. Quality and safety are continuously verified against large and diverse real-world corpora, including public test sets widely used in PDF quality validation (GovDocs1, veraPDF, Mozilla pdf.js, Isartor).
• "Never output a broken file" is the top design priority. If a file can't be compressed safely, you get the original back untouched.

4. Verify it yourself

You don't have to take our word for it. You can confirm that nothing is uploaded:

• Try airplane mode / Wi-Fi off — compression keeps working with the network fully disconnected. That is the strongest proof no data leaves your device.
• Check the browser dev tools — press F12, open the Network tab, and watch while you load the page and compress files: no requests to external domains ever appear.
• Check the Content-Security-Policy — this site ships a CSP (default-src 'self', connect-src 'self') that makes the browser itself block any external request. You can see it in the response headers.

Operator: Sveltiq