What SumatraPDF and www.sumatrapdfreader.org collect, why, and how long it is kept.
Last updated: September 24, 2026.
In short: your documents never leave your computer. SumatraPDF contacts our server to check for updates and to send a report when it crashes. The website has no ads, no analytics and no cookies. We don’t sell or share data for marketing.
Your documents #
SumatraPDF opens, displays, edits and prints documents on your computer. It doesn’t upload documents, their names, or the list of files you have read. The list of recently opened files is kept only in the settings file on your computer (see How we store settings).
Update checks #
When
CheckForUpdates is on (the default), SumatraPDF asks www.sumatrapdfreader.org whether a newer version exists: at most once a day in a release build, and on every start in a pre-release build. The request includes:- the SumatraPDF version
- the Windows version, whether SumatraPDF is 32 or 64-bit and whether it’s an ARM build
- the language of the user interface
- the version of Microsoft Edge WebView2, if installed, and whether SumatraPDF was installed from the Microsoft Store
- which CPU instruction sets (SIMD) are available
Our server stores each request with your IP address. We use it to count how many people use each version and to decide how fast to roll out new versions.
To turn update checks off, set
CheckForUpdates = false in Advanced settings.Crash reports #
When SumatraPDF crashes, official builds send a crash report to www.sumatrapdfreader.org. A report contains:
- a minidump: a snapshot of the program’s state at the moment of the crash (the call stacks of its threads and the memory they point to), which can include fragments of the document that was open
- your SumatraPDF settings, without the list of recently opened files
- the version and system information listed under update checks
- your IP address
We use crash reports only to find and fix bugs. They are deleted after 31 days.
Features that use other services #
These features send data to another service only when you use them:
- AI Chat with document sends your questions and text from the document to the AI provider you choose, with your own account or API key. That provider’s privacy policy applies.
- Search and translate a selection (Customize search / translation) opens the service in your web browser with the selected text.
- Ask AI in the documentation’s search box opens the AI site you pick with your question.
Read Aloud uses the voices installed in Windows. SumatraPDF doesn’t send the text anywhere.
The website #
www.sumatrapdfreader.org doesn’t use cookies, analytics, ads or tracking scripts. Like most web servers, ours logs each request: the time, the address of the page, the page you came from, your browser’s user agent and your IP address. We use the logs to run and fix the website.
The website remembers your choice of color theme and whether the documentation sidebar is hidden in your browser’s local storage. It stays in your browser.
Some documentation pages embed YouTube videos from youtube-nocookie.com. YouTube doesn’t set cookies until you play a video; when you do, Google’s privacy policy applies.
Service providers #
We don’t sell data or share it for advertising. The data above is processed by the companies that run our infrastructure:
- Hetzner (the web server)
- Cloudflare (network delivery of the website and file downloads, files.sumatrapdfreader.org)
- S3-compatible cloud storage (crash reports and update-check statistics)
- Upstash (update-check counts)
YouTube uploads #
“SumatraPDF video uploader” is a tool with which the SumatraPDF developers upload videos to the SumatraPDF YouTube channel, using the YouTube API. It accesses only that channel and doesn’t access data of other YouTube users.