Add a Text Watermark to a PDF, Such as For KYC Only
Stamp a diagonal grey text across every page of an ID or certificate copy before you hand it over.
Drop a PDF here
Watermarking happens entirely in your browser and the file is never uploaded anywhere.
About this tool
Banks, telecom outlets, hostels, landlords and coaching centres all ask for a copy of your Aadhaar or PAN. Banks and cyber safety advisories commonly suggest writing the purpose and date on any such copy, for example For bank KYC only, so that the same copy cannot be reused for a loan or a SIM in your name. On a PDF copy there is nowhere to write by hand.
This tool draws a line of text diagonally across the middle of every page of a PDF. The text is large, grey and semi-transparent, so the details underneath stay readable while the copy is clearly marked. The same setting works for stamping SAMPLE or DRAFT on a certificate you are sharing for checking.
The watermark is applied by your browser with the pdf-lib library and the file is never uploaded, which is the point when the document is an identity proof.
How to watermark a PDF
- Drop the PDF copy of the document on the upload box.
- Type the watermark in the Watermark text box, for example For bank KYC only 13/10/2026. The text is sized to fit the page, so a full purpose and date on one line is fine.
- Drag the Opacity slider. It runs from 10% to 80% and starts at 30%.
- Press Apply watermark and wait for the green Ready panel.
- Press Download. The file is saved with -watermarked added to the original name.
- Open the download and confirm the name, number and photo underneath are still legible. If not, lower the opacity and press Apply watermark again; each run starts from the original, so marks do not pile up.
Options and fixed settings
Only the words and their strength are adjustable. Everything else is fixed so that the result is consistent and the controls stay simple on a phone. The line is centred on the page and runs upward to the right at 45 degrees, sized so that it fits across the page diagonal.
| Setting | Value | Adjustable |
|---|---|---|
| Watermark text | Any single line; starts as SAMPLE; the button stays disabled while the box is empty | Yes |
| Opacity | 10% to 80%, default 30% | Yes |
| Font | Helvetica Bold | No |
| Colour | Mid grey | No |
| Angle | 45 degrees, rising to the right | No |
| Size | Fits the page: up to one eighth of the shorter side, smaller for a long line so it never runs off the page | No |
| Pages | Every page in the file | No |
Choosing the text and opacity
The text is scaled to the page. A short word such as SAMPLE comes out large; a longer line such as For bank KYC only 13/10/2026 is shrunk until it fits 80% of the diagonal, which on an A4 page is still easily readable. Keep to one line of roughly 10 to 40 characters; beyond that the text gets small enough to lose its purpose.
At 30% the text reads clearly on a white certificate and the printed details remain easy to read. Go up to 50% or 60% for a dark or busy scan, and stay nearer 20% when the document has small print you need a clerk to read. Above 70% the text starts to cover the content it sits on.
The built-in font covers English letters, digits and common punctuation. Text in Hindi or another Indian script, and symbols such as the rupee sign, cannot be drawn by this font and the tool shows an error. Use the English form of the purpose instead.
What a watermark does and does not protect
- The text is drawn as a separate layer on top of the page, not merged into the scan image. Someone with PDF editing software can delete that layer. Treat the watermark as a clear statement of purpose and a deterrent to casual misuse, not as a lock.
- For Aadhaar, UIDAI's masked Aadhaar download hides the first eight digits of the number. Where the receiving office accepts it, a masked copy plus a purpose watermark is the safer combination.
- A printed copy keeps the watermark, since it is part of the page content. If you print the watermarked PDF and sign the printout, the purpose line and your signature travel together.
- Encrypted PDFs cannot be opened and show an error. The output is a few kilobytes larger than the input because of the added text; the scan itself is not recompressed.
Watermarking runs entirely in your browser. The identity document is never uploaded and is cleared from memory when you close the tab.
Frequently asked questions
›What should I write on an Aadhaar photocopy given for KYC?
The usual advice from banks and cyber safety campaigns is the purpose and the date, so that a copy marked for one use is harder to reuse elsewhere. For bank KYC only 13/10/2026 is the common form, and it fits on one line because the tool sizes the text to the page. Pair it with a masked Aadhaar where the receiver accepts one.
›Can a watermark be removed from a PDF?
Yes, by anyone with a PDF editor, because the text is a separate object drawn over the page. It will survive viewing, printing and ordinary sharing, and it clearly signals the purpose to the person handling the copy, but it is not a security measure. Do not rely on it alone for a document you would not otherwise share.
›Can I watermark only the first page of the PDF?
Not with this tool, which stamps every page with the same text. For a single page, extract that page into its own PDF with Extract pages, watermark it, and then merge it back with the rest using Merge PDF. For a one page ID copy this does not arise.
›Can I use a Hindi watermark?
No. The tool uses the standard Helvetica Bold font, which has no Devanagari or other Indian script glyphs, so Hindi text cannot be drawn and the tool reports an error instead of producing a file. Write the purpose in English letters, for example Kewal bank KYC ke liye if you want it in Hindi words.
›What opacity should I use so the document stays readable?
Start at the default 30%. On a clean white certificate or Aadhaar PDF that is visible without hiding the text underneath. If the scan is dark or has a coloured background, move up to around 50%. Check the download by zooming in on the smallest printed numbers; if they are hard to read, lower the slider and apply again.
›Will the watermark show when the PDF is printed?
Yes. It is part of the page content, so it prints in grey at the same opacity on every page. A printout of a watermarked Aadhaar copy therefore carries the purpose line, which is the outcome you want when a bank or hostel keeps a paper copy in its records.