Question 1

Where are my files actually processed?

Accepted Answer

Inside your browser tab. JavaScript and WebAssembly read your file from local memory, perform the requested operation, and offer the result as a download. No upload happens.

Question 2

Can you see my documents?

Accepted Answer

No. We have no upload endpoint for PDFs and no server-side storage. The file you process never leaves your device.

Question 3

How is that possible?

Accepted Answer

Modern browsers expose a File API that lets web pages read files the user explicitly chooses. The open-source pdf-lib and pdf.js libraries can manipulate those files entirely in JavaScript. We compose them into tools.

Question 4

How can I verify it?

Accepted Answer

Open your browser developer tools, switch to the Network tab, run a tool, and watch. You will see no upload of your document.

Question 5

Do I need an account?

Accepted Answer

No. Every browser-based tool works without sign-up.

Question 6

Is there a file-size limit?

Accepted Answer

There is no hard server limit because nothing is uploaded. The practical limit is your device memory. Most modern phones and laptops comfortably handle 200 MB+ files.

Question 7

Does it work on mobile?

Accepted Answer

Yes. iOS Safari and Android Chrome both support the underlying APIs. Very large files may be slower on phones.

Question 8

Do I need an internet connection?

Accepted Answer

You need internet to load the tool page itself the first time. After that, the actual processing of your file does not need internet.

Question 9

Is everything really free?

Accepted Answer

Every tool on the site is free to use without a card or account. The free tier is ad-supported. A Pro tier (coming soon) removes ads and adds heavier features.

Question 10

Will you sell my data?

Accepted Answer

No, and we don't have document data to sell because we never receive it. Standard hosting request logs are not sold either.

Question 11

The tool seems frozen on a large file.

Accepted Answer

Large files take longer because all processing is local. A 100 MB PDF can take 10–30 seconds on a typical laptop. Mobile devices may be slower. Close other heavy tabs if it stalls.

Question 12

My PDF is encrypted and the tool failed.

Accepted Answer

Use the Unlock PDF tool first with the password you set. Then run your operation on the resulting unlocked file.

Question 13

Where do I report a bug?

Accepted Answer

Email support@pdfsamurai.co.uk with a description of the issue and your browser version.

Frequently asked questions.

How privacy works here.

Day-to-day use.

No accounts, no surprises.

When something feels off.