Are online PDF tools safe? How to check before you upload
We send passports, contracts and bank statements through PDF tools without thinking about it. Before you upload anything sensitive, it helps to know what actually happens to the file.
Two kinds of tools
Many online services upload your file to their server, process it there and send it back. Others run entirely in your browser, so the file never leaves your device. The second kind is safer for private documents, because there is no copy on someone else's computer to worry about.
How to tell which kind you are using
- Read the privacy policy. A trustworthy service says clearly whether files are uploaded and how long they are kept.
- Open the Network tab in your browser developer tools while processing a file. A large upload request means the file is being sent.
- Load the page, turn off your internet connection and try the tool. If it still works, the processing is local.
A short safety checklist
- The address starts with https and the site has a real privacy policy.
- It does not demand sign-up or an installation for a simple task.
- It does not ask for permissions it has no reason to need.
- It states what happens to your files after processing.
Reduce the risk yourself
- Protect important files with a password using Protect PDF before sending them.
- Remove hidden information such as author names and editing history with Clean PDF metadata.
- When hiding sensitive text, use a real redaction tool such as Redact PDF. Drawing a black rectangle over text often leaves the text underneath.
- Delete downloaded copies you no longer need.
How Listok works
Every Listok tool runs inside your browser on your own device, and the files are not sent to our servers. You can read the details on the Privacy page.