A PDF24 alternative that never uploads your files
PDF24 is free, broad, and popular, and it comes in two forms: a website and a Windows desktop app. The desktop app, PDF24 Creator, works offline and keeps files on your PC. The website works like most PDF sites and uploads your file to its servers. InstantTools gives you the local version without installing anything.
What we saw when we tested it
On October 4, 2026 we chose a small test PDF on PDF24's Compress PDF page and recorded every request the page sent. Code inside the page checked each request body for the file.
Method, all three sites, and how to check any site yourself: Where does your PDF go when you compress it online?
Where your file goes
On the PDF24 website, your file is sent to a PDF24 file server, processed there, and offered back as a download. In our test the whole file left the browser the moment it was chosen. If you are on Windows and can install software, PDF24 Creator avoids the upload entirely; PDF24 says so on its own download page.
InstantTools runs the PDF engine in your browser tab, on any operating system, with nothing to install and no admin rights needed. That covers locked-down work laptops, Macs, Chromebooks, and borrowed computers. Load a tool once and it keeps working with your Wi-Fi off.
The same jobs, done locally
Honest questions
Is PDF24 safe to use?
It is a long-running, reputable service. The website uploads your file to process it, which means trusting PDF24 with a copy. The PDF24 Creator desktop app for Windows processes files on your PC instead.
Should I use PDF24 Creator or InstantTools?
If you are on Windows and can install software, PDF24 Creator is a solid local option with more features. If you are on a Mac, a Chromebook, a phone, or a work laptop where you cannot install apps, InstantTools gives you local processing in the browser.
Does the PDF24 website upload my file even before I click compress?
In our test, yes: the file was sent as soon as it was chosen, before any other click. You can watch this yourself in your browser's developer tools, on the Network tab.
Verify it yourself
Open your browser's developer tools, switch to the Network tab, and use any InstantTools file tool. After the page and its engine load, you will see no request carrying your file. That check takes thirty seconds and beats any privacy policy.