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Kitofy

How we keep your files safe

Files are processed on your device and are never uploaded to our servers. Here is how it works and what is stored in the browser.

  1. Your fileRead by the browser locally
  2. BrowserWebAssembly in Web Workers
  3. ResultSaved on your device
The whole process takes place on your device: there is no server that receives your files.

Processing happens in your browser

When you add a file, the browser reads it locally. Most engines for images, video, audio, PDF, documents and archives are compiled to WebAssembly and run in Web Workers - separate background threads of the same page.

The contents of your files are not sent anywhere: there is simply no server that would receive them. The internet is needed only to load the page and the engine for the format, and after that the processing speed depends on the power of your device.

Which engines are used

We use proven open-source projects adapted to work in the browser. The main ones are listed below; the full list with licenses and links to the source code is on the Licenses page:

  • jSquash (MozJPEG, libwebp, libavif, libjxl, OxiPNG), libheif and ImageMagick - images, HEIC photos and camera RAW files;
  • Mediabunny with WebCodecs and FFmpeg - video and audio;
  • pdf.js, pdf-lib and qpdf - PDF;
  • Tesseract - text recognition;
  • 7-Zip and libarchive - archives;
  • fonteditor-core and harfbuzzjs - fonts;
  • office2pdf - Word, Excel and PowerPoint documents to PDF.

Check it yourself

You don't have to take our word for it - you can make sure the file doesn't leave your device in a minute:

  • open the browser developer tools (F12 or Ctrl+Shift+I, on a Mac - Cmd+Option+I) and go to the Network tab;
  • add a file and start processing;
  • look at the requests: the browser loads only the page code and the engines, and after the result is ready it sends short statistics with the pair of formats (see Privacy). There will be no request in the list that transfers your file.

What is stored in the browser

Large results are temporarily stored in the browser's private storage (Origin Private File System) so they can be downloaded without using too much memory. They are deleted when you remove a file from the list, and data from old sessions is automatically cleared after 24 hours.

The browser's local storage keeps the last settings for each format so you don't have to choose them again, as well as the number of completed operations and the date when to ask you to rate the service again. The files themselves are not saved there.

Metadata is not copied

When processing images, EXIF data - the camera model, shooting date and GPS coordinates - is not transferred to the result. The photo orientation is applied to the pixels, so the image is not turned sideways.

The exception is when compression didn't make the file smaller: then the site returns the original file as it is, together with its metadata, and marks the result as "unchanged". For PDF there is a separate option to remove the document properties.

Recommendations

Use an up-to-date browser - it has the latest security fixes and supports more codecs. On a shared computer, clear the file list and the browser data after working with confidential documents.