Check that your PDF is never uploaded
Every Slate PDF tool except Translate PDF processes your file inside your own browser. You don’t have to take our word for it: the two tests below take about two minutes and work on any website, so you can compare us with any other PDF tool.
Does Slate PDF upload your files?
No. When you merge, compress, convert, sign or edit a PDF here, the file is opened by JavaScript running on your device and the result is saved straight back to your device. No copy of the document is sent to a server, so there is nothing for us to store, read or delete.
- Your file never leaves your device.
- No account and no server-side storage.
- The one exception: Translate PDF sends the extracted text to a translation service.
Test 1: watch the Network tab
- Open a tool, for example Merge PDF, in Chrome, Edge or Firefox.
- Press F12 (or right-click → Inspect) and open the Network tab.
- Click the clear button so the list is empty.
- Add your PDF and run the tool, then download the result.
- Look at the list. An upload would appear as a request about as large as your file. You will not find one.
Test 2: airplane mode
- Open the tool page and wait for it to finish loading.
- Turn on airplane mode, or unplug from the network.
- Add your PDF and run the tool. It still works, because nothing needs a server.
Run the same test on a tool that uploads files and it fails as soon as it tries to send the document. (OCR tools need to download their language model once while online; after that they work offline too.)
Every request Slate PDF makes
| What | What is sent |
|---|---|
| The page itself | HTML, scripts, styles and fonts from slatepdf.space — the same for every visitor. |
| Text-recognition model (OCR tools only) | OCR PDF and Scan PDF download the recognition engine and a language model (a few MB) once from cdn.jsdelivr.net. This is a download; your file is not sent. |
| Analytics | Google Analytics and Vercel record that a page was viewed. They never receive your file or its contents. |
| Star ratings | If you rate a tool, your 1–5 score is sent to slatepdf.space/api/rating. Nothing else. |
| Translate PDF (the one exception) | The text extracted from your PDF is sent to a public translation service (Lingva, LibreTranslate or MyMemory). The tool warns you before it does. |
Frequently asked questions
Do online PDF tools upload my files?+
Most do: the file is sent to the provider’s server, processed there and deleted later, usually after one to twenty-four hours. Slate PDF works differently — the PDF is read and written by code running in your browser, so the file itself is never sent anywhere.
How can I tell whether a PDF website uploads my file?+
Open your browser’s developer tools, go to the Network tab, then run the tool. An upload shows up as a request whose size is roughly the size of your file. Or load the tool, turn on airplane mode, and run it: a tool that needs a server will fail.
Does any Slate PDF tool send data online?+
Translate PDF sends the text it extracted to a public translation service, and says so before you start. No other tool sends your document or its contents anywhere.
Is it safe for confidential documents?+
Because the file never leaves your device, there is no copy on someone else’s server to leak or retain. Avoid Translate PDF for confidential text, and keep your device itself secure.
Ready to try it? See all PDF tools.