Diagonal DRAFT stamp on a contract
You're sending a contract to a counterparty for review and want every page clearly marked as a draft. Type DRAFT, pick the diagonal preset, set opacity to 30%, and a 45° stamp lands across every page in seconds.
Watermark PDF
Watermark PDFs entirely in your browser
No uploads. No watermark on the output. No size limits. Filoraio stamps a custom text or image watermark on every page of your PDF — locally on your device, with a live preview before you download.
Last reviewed ·by the Filoraio team
- Runs entirely in your browser
- No file uploads
- No account required
How your file moves
Your document never leaves this tab.
Filoraio runs the merge directly inside your browser using a small WebAssembly engine. Nothing is uploaded, nothing is queued, and you can verify it yourself — open your browser’s DevTools, switch to the Network tab, and watch it stay quiet.
- 01
You pick the files
They’re read into your browser’s memory through a standard file picker.
- 02
Your CPU does the work
The merge runs locally — no request leaves your device while it processes.
- 03
You save the result
The combined PDF lands in your downloads folder, the same way any other download would.
- 04
Network stays asleep
No upload bar, no progress spinner waiting on a server. Works offline once the page is loaded.
Step by step
How to watermark a PDF in four steps
From upload to download takes well under a minute. The live preview means you never have to download-then-redo to see the result.
Add your PDF
Drag a PDF onto the picker or click to choose one. The file stays on your device — no upload, no quota, no account.
Choose text or image
Type a word or phrase (DRAFT, CONFIDENTIAL, your company name), or upload a PNG/JPG logo. Switch modes any time without losing your settings.
Adjust position, opacity, rotation
Pick from nine corner/edge anchors or the diagonal preset. Drag the sliders for opacity and rotation. The preview updates as you go.
Save the watermarked PDF
Click Apply. The watermark is stamped on every selected page locally, and the new PDF downloads to your device — no Filoraio watermark on the output.
Who it’s for
Who uses Filoraio to watermark PDFs
Anywhere a PDF needs to carry a visible badge — draft status, confidentiality, ownership, or a brand mark — this is the tool you reach for.
Legal teams
Stamp DRAFT or PRIVILEGED across exhibit bundles before circulation so a leaked copy can't be mistaken for the executed version.
Designers & agencies
Mark client deliverables with a SAMPLE or PROOF watermark before invoice clearance so unpaid drafts can't be repurposed.
Photographers
Add a copyright logo or photographer's name across every page of a portfolio PDF before sending to galleries or licensing prospects.
HR & operations
Brand offer letters, policy documents, and employee handbooks with the company logo so circulated copies stay visibly first-party.
Realtors
Add brokerage branding to listing PDFs and floor plans so buyers and agents always know which firm produced the document.
Researchers & writers
Stamp UNDER REVIEW or DO NOT CITE on manuscript drafts circulated to co-authors so an early version can't be mistaken for the final.
In practice
Real situations this tool solves
Four common reasons people search for a way to watermark a PDF — and the exact workflow each one collapses into.
Company logo on a proposal
Your client proposal needs your brand mark on every page. Switch to image mode, upload your transparent PNG logo, anchor to top-right at 20% width, set opacity to 80%, and every page carries the brand badge consistently.
Photographer copyright across a portfolio
You're sending a portfolio PDF to a licensing prospect. Add © Your Name 2026 at 25% opacity in the bottom-right of every page so the work is clearly attributed without dominating the imagery.
CONFIDENTIAL stamp on selected pages only
Pages 1-5 of your report contain financial detail and need a CONFIDENTIAL stamp; the rest is public. Switch the page selector to ranges, type 1-5, and only those pages get the stamp — the public pages download untouched.
Pro tips
Tips for cleaner PDF watermarks
Four small habits that turn a quick watermark into a perfect one — especially when the watermark needs to coexist with dense content underneath.
Keep opacity between 20% and 40%
Above ~50% the watermark obscures the underlying text; below ~15% it's barely visible. The 20–40% sweet spot is what every PDF reader expects from a watermark — readable, present, not overwhelming.
Use a transparent PNG logo, not a JPG
JPGs always have a white (or coloured) background — they look like a sticker on top of your PDF. Export your logo as a transparent PNG so only the artwork shows over the content; the background just disappears.
Diagonal works best for status words
DRAFT, CONFIDENTIAL, VOID, SAMPLE — these are status badges and the diagonal preset is the universal visual language for them. For brand logos and copyright marks, prefer a corner or edge anchor so the mark reads as a badge rather than a status.
Match font size to page count, not page width
A 60pt CONFIDENTIAL stamp on a single A4 page looks balanced. The same stamp on 100 pages of dense text feels heavy because the eye registers it dozens of times in a row. For longer documents, try 36–48pt to reduce visual fatigue.
How it compares
How Filoraio's watermarker compares to typical online tools
Side by side with the average online PDF watermark tool — including the ones with millions of monthly users.
| Feature | Filoraio | Typical online PDF tools |
|---|---|---|
| Where files are processed | On your device | Uploaded to servers |
| Live preview before download | Yes — updates as you type | Often download-then-check |
| Filoraio watermark on output | None | Often added on free tier |
| Account required | No | Often required for full access |
| Daily watermark cap | Unlimited | Often 2–5 per day |
| Text + image modes | Both, with full controls | Often only one mode free |
Questions
Common questions about Watermark PDF
Quick answers to the things people ask most often before using this tool.
Is this PDF watermark tool really free, with no catch?
Yes. No account, no email, no daily quota, and no watermark from Filoraio on the output. The page is supported by ads — never the file you download. Watermark as many PDFs as you need.
Are my files uploaded somewhere?
No. The watermark is applied entirely on your device using a small WebAssembly library. Your PDF never leaves the browser tab — which is why this works offline and on confidential files.
How do I add a diagonal DRAFT watermark across every page?
Type DRAFT in the watermark text field, pick the diagonal preset (button below the position grid), set opacity around 30%, and click Apply. The stamp lands at a -45° angle across the centre of every page — the canonical legal/draft watermark style.
Can I use a transparent PNG logo as a watermark?
Yes. Switch to Image mode, upload your transparent PNG, and the watermark renders with the background fully transparent — only the logo art appears over your PDF content. Transparent backgrounds are strongly recommended over JPG (which always carries a coloured background).
Can I watermark only specific pages?
Yes. In the Pages section, switch to Specific pages and type ranges like 1-5, 8, 12-20. Only those pages get the watermark; the rest download unchanged. Useful when only the cover or selected sections need a stamp.
What's the best opacity for a watermark?
20–40% is the sweet spot for most documents. Below 15% the watermark becomes invisible against busy backgrounds; above 50% it starts to obscure the underlying text. Diagonal status stamps (DRAFT, CONFIDENTIAL) tend to look right around 25–35%.
Does the watermark appear in print as well as on screen?
Yes. The watermark is written into the PDF itself — it's not a viewer overlay. Anyone who opens, prints, or screenshots the file sees the watermark exactly where you placed it, at the opacity you chose.
Will the watermark survive if someone re-saves the PDF?
Yes for normal viewers (Acrobat, Preview, Chrome). The watermark is part of the page content stream, the same as any other text or image. Someone with advanced PDF editing software could remove it, but it can't be removed by accident or by a routine save.
How do I watermark a PDF on a Mac without using Preview?
Open this page in Safari or Chrome, drop your PDF, pick your watermark, and click Apply. The new PDF downloads to your Mac instantly. Works on Apple Silicon and Intel — no app install, no Apple ID.
Can I watermark a PDF on an iPhone or iPad?
Yes. Open this page in Safari, tap the drop area, pick a PDF from the Files app, tweak the watermark, and tap Apply. The result saves directly to Files. The interface is fully touch-friendly — no app install, no third-party app.
Why does my image watermark look pixelated?
The source image is being scaled up beyond its native resolution. Use a higher-resolution PNG (at least 600×600 px is comfortable for a corner badge; 2000×2000+ for a full-page diagonal). Vector logos exported as PNG at 300 DPI typically render perfectly.
Can I watermark a password-protected PDF?
Not directly — encrypted PDFs need to be unlocked first. Our Unlock PDF tool removes owner restrictions automatically and decrypts password-protected files locally when you supply the password. Then drop the unlocked output here to add your watermark.
How do I remove a watermark from a PDF instead of adding one?
Filoraio doesn't currently remove watermarks — that's a much harder problem because the watermark becomes part of the page content. If the PDF has owner-side restrictions (no print, no copy), our Unlock PDF tool removes those. True watermark removal usually requires a desktop PDF editor like Acrobat Pro.
What's the maximum file size I can watermark?
There's no hard cap. The watermark runs in your browser's memory — the practical limit is your device's available RAM. Most browsers handle 100+ MB PDFs without trouble; 500+ MB scanned documents work too but take a few extra seconds.
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