Privacy
PDFKilo processes files right in your browser. We never receive your documents, never store them and cannot see them.
Updated: October 5, 2026
Your files never leave your device
Every PDFKilo tool runs on your device. PDF compression is done by Ghostscript, and Word, Excel and PowerPoint to PDF on a computer is done by LibreOffice. Both are compiled to WebAssembly and run inside the browser. Merging, splitting and converting PDF to other formats run in JavaScript, also in the browser.
The files you choose are read only in your browser's memory. They are not sent to our server or anyone else's, and nothing of them remains once you close the tab. That makes PDFKilo safe for passports, contracts, certificates and other personal documents.
What the site downloads
To process a file, your browser downloads an engine from pdfkilo.com: about 16 MB for compression, and about 76 MB for converting office documents to PDF on a computer. This is an ordinary download of the site's code: the engine comes to you, your file does not come to us. The office engine is kept in the browser cache so it does not download again.
The site's fonts are also served from pdfkilo.com, without calls to third-party services.
What your browser stores
If you switch the language with the RU and EN buttons, the choice is saved in your browser's local storage (localStorage) so the site opens in that language next time. This stays on your device.
PDFKilo's own code sets no cookies, has no accounts and never asks you to sign up. Google's ads may set cookies, as described below.
Google AdSense ads
The site is free and is funded by Google AdSense ads. Google and its partners may use cookies and similar technologies to show ads based on your previous visits to this and other websites, and to measure how ads perform.
How Google uses information from sites that use its services: policies.google.com/technologies/partner-sites. How Google uses cookies in advertising: policies.google.com/technologies/ads.
You can turn off personalised Google ads in Google Ads Settings, and ads from other participating companies at aboutads.info. Ads never get access to the files you process.
Hosting
The site is hosted on Cloudflare. Like any host, Cloudflare processes technical request data (IP address, browser type, the page requested) to deliver pages and protect the site from attacks. Your files are never part of these requests.
Open source
PDFKilo's code is open under the AGPL-3.0 licence: github.com/C0urtCl0wn/PDFCompress. Anyone can check that files are processed only in the browser.
Questions and suggestions are welcome on the project's GitHub issues page.