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Free Online Watermark Tool

Add text or logo watermarks to PDFs & images — no upload, no signup

This tool is free because we want to promote data ownership and make it accessible to everyone. You shouldn't need an account or have to wonder what happens to your files after you hit upload. Private by design means just that — everything runs directly in your browser, your files are never sent anywhere, and there's nothing for us to store or share.

Make it traceable, not just visible. Use specific dates, names, or codes — a generic "CONFIDENTIAL" tells you nothing if a file leaks. Click any example to use it.
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PDF · PNG · JPG · WEBP  |  Max 50 MB

Watermark Settings

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Your files are processed entirely in your browser. Nothing is ever uploaded to any server.

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Preview

Upload a file to see the live watermark preview

How to add a watermark to a PDF or image

  1. 1

    Upload your file. Click the upload area and select a PDF or image file (JPG, PNG, WebP, GIF, BMP). The file is loaded entirely in your browser — it is never sent to a server.

  2. 2

    Enter your watermark text — or upload a logo. Type the text you want to overlay on the file, or switch to Logo mode and upload your own PNG or JPG. Use a specific date, name, or identifier to make the watermark traceable rather than generic.

  3. 3

    Customise the watermark. Adjust font size, opacity, color, rotation, and position. Choose a pattern: Single places one watermark at a chosen position; Tiled repeats it across the whole page; Mirror adds the text alongside a horizontally mirrored copy.

  4. 4

    Download the watermarked file. Click Download. The watermark is applied instantly in your browser and the file is saved to your device. No data is uploaded or stored anywhere.

Why watermark your files?

A watermark marks a document or image as yours — and makes it traceable. Freelancers and studios watermark client proofs and drafts so unpaid work can't be used as final. Businesses watermark contracts, invoices, and confidential documents with a recipient name and date, so if a file ever leaks, the watermark shows exactly when and to whom it was shared. Photographers and artists add logo watermarks to protect portfolio images from unauthorised reuse.

Most online watermark tools upload your file to their servers to process it. This one doesn't: everything runs client-side in your browser, which means it also works with sensitive documents you wouldn't upload to a random website.

Watermarking is one layer of protection — if you need real control over a file, combine it with view-only file sharing (the recipient can look but never download), a signed NDA or copyright agreement attached to the transfer, or expiring links. You can also grab free contract templates and sample legal letters from our docs & tools collection.

Frequently asked questions

Is this watermark tool really free?

Yes. The OONOO watermark tool is completely free with no signup, no subscription, and no usage limit.

Do my files get uploaded to a server when I use this tool?

No. All processing is done entirely in your browser using client-side JavaScript. Your files never leave your device and are never sent to any server.

What file types does the watermark tool support?

The tool supports PDF files (the watermark is applied to every page automatically) and image files including JPG, JPEG, PNG, WebP, GIF, and BMP.

Can I use my own logo as a watermark?

Yes. Switch the watermark type to Logo and upload a PNG or JPG image. The logo is overlaid on your PDF or image with the same size, opacity, rotation, position, and pattern controls as text watermarks.

What watermark patterns are available?

Three patterns are available: Single places one watermark at a chosen position on the page. Tiled repeats the watermark in a grid across the whole page. Mirror places the watermark text alongside a horizontally mirrored copy side by side.

What text should I use for a watermark to make it traceable?

Use specific identifiers rather than generic words like CONFIDENTIAL. Good examples: a date and name (e.g. 'Maria Chen · 2026-06-29'), a project code (e.g. 'PROJ-2847 DRAFT'), or a recipient name with a date. Specific watermarks identify exactly when and to whom a file was shared if it ever leaks.

Does the watermark tool apply to all pages of a PDF?

Yes. The watermark is applied to every page of the PDF automatically. The preview shows the first page; the downloaded file contains the watermark on all pages.

Need to share files securely?

OONOO lets you send files with view-only access, custom agreements, e-signatures, ID verification, and more.

Explore OONOO →