Privacy & uploaded files
What happens to the PDFs you upload and to the other data Preflighter.app handles. Short and specific.
Uploaded PDFs
- Your PDF is processed on my own server. No cloud service renders it.
- The file and all its previews are deleted automatically 24 hours after it was last opened. If the server runs low on disk space, the oldest files go sooner.
- Each document gets a random ID. The server only sends back previews of the separations. It never hands out the original PDF to anyone, not even to you.
- I don't open, share or sell uploaded PDFs, and I don't use them for anything else, including AI training.
Exception: a PDF attached to a bug report
The feedback form has a checkbox “Attach the open PDF to this report”. If you leave it ticked, the PDF is stored with the report and the 24-hour deletion does not apply to it. Without the file, most bugs can't be reproduced.
- I download attached PDFs to my own computer only to reproduce the bug, test the fix and improve the tool.
- I never pass them on, publish them or use them for anything else.
- On the server they are deleted automatically after 12 months. I delete the copy on my computer within the same period. Email me and I'll delete it sooner.
- If you don't want to attach the PDF, untick the box before sending.
Bug reports and feedback
A report stores:
- your message and your email if you enter one (optional),
- your IP address, to limit spam and abuse of the form,
- your browser type (User-Agent) and the technical state of the open document (e.g. “loaded”), to track down the bug.
I get notified of new reports via Telegram: the message, email, browser and the ID of the attachment. Neither the IP address nor the PDF itself is sent through Telegram.
Reports are deleted from the server automatically after 12 months.
Anonymous statistics
For each uploaded PDF a technical record is kept: file size, page count, PDF version, the program that created it (Creator/Producer), page size, output intent, number of plates and spot colours, and whether it contains RGB, transparency and embedded fonts. The record contains no file name, no content and no IP address, and it can't be linked to a person. It helps me decide what to improve.
Analytics and cookies
Traffic is measured with Umami. Umami uses no cookies, stores no personal data and shows only aggregate numbers (visits, referrers, clicks). That's why there is no cookie banner.
Who else sees the data
| Cloudflare | Serves the website and carries traffic between you and my server (HTTPS). In transit it sees your IP address and the uploaded file, but doesn't store it. |
|---|---|
| Umami | Cookieless traffic analytics, see above. |
| Telegram | Notifications about new reports, see above. |
I don't pass data to anyone else.
Data controller and contact
The data controller is Lukáš Opekar, a private individual based in the Czech Republic. Contact: [email protected].
Legal basis
- Processing the uploaded PDF: the service you request by uploading the file (Art. 6(1)(b) GDPR).
- Reports, IP address and browser: legitimate interest in fixing bugs and preventing abuse (Art. 6(1)(f) GDPR).
- Email in a report: your consent to be contacted about the report (Art. 6(1)(a) GDPR). You can withdraw it at any time by email.
Your rights
You have the right to access, rectify and erase your data, to restrict its processing, to data portability and to object. Just write to [email protected]. To help me find a report, include the approximate date and your email or the start of the message. Uploaded PDFs without a report are gone after 24 hours, so there is nothing left to hand over or delete.
You can lodge a complaint with the Czech data protection authority, ÚOOÚ (uoou.gov.cz), or with the authority in your own EU country.
Last updated: 30 September 2026