You can add a watermark to PDF files here by typing a word or short phrase and choosing how strong it should look. The tool stamps your text diagonally across the centre of every page, the classic "DRAFT" or "CONFIDENTIAL" look. It's free, needs no account, and works in the browser on your phone or computer.
Steps to stamp a PDF
- Type your watermark text, for example DRAFT, SAMPLE, COPY or your business name.
- Choose a strength: Light, Medium or Strong.
- Add your PDF by tapping "Select files" or dragging it onto the page.
- Apply the watermark and download the stamped file.
The same text goes on every page of the document. If you upload several PDFs, they all get the same watermark and come back together in a ZIP.
What the strength setting changes
Strength controls how visible the watermark is over your content.
| Strength | How it looks | Good for |
|---|---|---|
| Light | Faint, easy to read through | Internal drafts, documents people still need to read comfortably |
| Medium | Clearly visible without hiding the page | Most uses: samples, proofs, shared copies |
| Strong | Bold and hard to ignore | Previews you don't want reused, "VOID" or "NOT FOR DISTRIBUTION" copies |
If you're unsure, try Medium first, then look at a page with lots of text on it. If the words underneath are hard to read, go down to Light. If the watermark is easy to overlook, go up to Strong.
Reasons to put a PDF watermark on a document
A watermark tells anyone who opens the file what it is and where it came from, and it stays on the pages when the file is forwarded or printed.
Freelancers and designers send clients a watermarked proof before payment. The client can review the work, and the "SAMPLE" stamp across each page makes it clear this isn't the final file.
Offices mark documents as DRAFT while they're still being reviewed, so nobody mistakes an early version for the signed one. Legal and HR teams often stamp CONFIDENTIAL on sensitive papers before sharing them internally.
Teachers and tutors who sell or share worksheets and notes can put their name or school on every page. Students sometimes do the same with study notes they post in group chats, so people know who wrote them.
People applying for jobs, flats or loans sometimes stamp copies of their ID or documents with a note like "Copy for ABC Bank application only". If the copy ends up somewhere else, the stamp shows what it was given for.
What this tool doesn't do
It adds text only. You can't use a logo or picture as the watermark. If you want your brand on the page, type your business name instead.
The position is fixed: diagonally across the centre. You can't move it to a corner or put it only on some pages. Every page gets the same stamp.
A watermark is a visible label. It discourages copying and shows where a file came from, but it doesn't stop anyone from opening or reading the PDF. If you need to control who can open the file, add a password with Protect PDF.
Tips
Keep the text short. A watermark of one to four words is easy to read at a glance, while a long sentence stretched across the page is harder to take in. Capital letters, such as DRAFT or SAMPLE, tend to stand out more than lowercase.
Keep your original unwatermarked file somewhere safe. Once the stamp is on, it's part of the page, so you'll want the clean version for the final copy you send after approval or payment.
If you only want certain pages watermarked, split those pages out first with Split PDF, stamp them, then put the document back together with Merge PDF.
For photos and images, use Watermark image instead. It works on JPG and other picture files.
On any device
The tool runs in your web browser on Android, iPhone, Windows, Mac, Linux and Chromebook. There's nothing to install. On a phone, tap "Select files" to pick the PDF. Each upload can be up to 100 MB.
What happens to your files
Your PDF is processed on our server and deleted as soon as the watermarked file is sent back to you. We don't keep it and we don't share it. The only watermark on the result is the one you typed: Xon File doesn't add its own name or logo.
Frequently asked questions
Is it free to add a watermark to a PDF?
Yes. It's free, there's no sign-up, and the only text added is the watermark you choose.
Can I use my logo as a watermark?
No, the tool supports text watermarks only. You can type your company or brand name as the watermark text instead.
Where does the watermark appear on the page?
Diagonally across the centre of every page. The position can't be changed, but you can make it lighter or stronger with the Strength setting.
Will the watermark make my document hard to read?
Not if you pick the right strength. Light keeps the text underneath easy to read, Medium is clearly visible, and Strong is the hardest to ignore. Check a busy page after stamping and redo it if needed.
Can I watermark a PDF on my phone?
Yes. Open this page in your phone's browser, type your text, choose a strength, tap "Select files" and pick the PDF. The stamped file downloads to your phone.
Can I stamp several PDFs at once?
Yes. Upload more than one PDF and they all get the same watermark. The results come back together in one ZIP.
Does a watermark stop people copying my PDF?
It makes copying less attractive and shows who the document belongs to, but it doesn't lock the file. Use Protect PDF if you need a password.