Browser tool · No install

Add a Watermark to a PDF

Stamp a text label or a logo across every page, with the opacity, angle and position set by hand. The mark is drawn on this device and the original file stays as it was.

Document format work by OnlinePCApps since 2013

No upload No sign-up Text or logo Free
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Price, always
Why watermark

Three Documents That Need a Mark on Them

Each of these carries a meaning the page itself does not state. A watermark says it on every page at once.

A Draft Going Out for Review

A version still being worked on can be mistaken for the final one. A DRAFT or CONFIDENTIAL label across each page makes the status plain and lowers the chance of the wrong copy being acted on.

A text mark states the status on every page in one pass.

A Proposal Without Branding

A proposal or a report sent to a client reads as anonymous without a name on it. A faint logo in the corner or behind the text ties the document to its source and looks considered.

A logo watermark carries the brand through the whole file.

A Sample That Could Be Reused

A preview or a sample shared widely can be passed on as though it were free to take. A SAMPLE or copyright mark tiled across the page marks ownership and is awkward to crop away.

A tiled mark repeats so it cannot be cropped off cleanly.
How it works

Add a Watermark in Three Steps

1

Load the PDF

Choose a PDF or drag it onto the panel above. It loads on the machine ready for a mark, and no copy is sent out.

DRAFT
2

Set the Watermark

Type a label or upload a logo, then set the opacity, the angle and where it sits. A live preview shows the mark on the page before it is applied.

DRAFT
3

Save the Marked Copy

The watermarked file downloads beside the original. The source PDF is left untouched, so a clean master is always kept.

Text or logo A typed label or an uploaded image
Opacity and angle Faint or bold, upright or diagonal
One spot or tiled A single mark or repeated across the page
Need it faster?

Stamp a Whole Folder at Once

Single files are quick to mark right here. When a directory of documents needs the same stamp, the desktop app reads each PDF and applies the watermark to every file in one run, straight from disk.

Get Desktop Version Free trial · Windows 7 to 11
What the tool does

A Mark Drawn Onto the Page

A watermark is text or an image painted over each page. The control over how it looks is what keeps it readable without hiding the content.

Text or a Logo

A text watermark carries a typed label such as DRAFT or CONFIDENTIAL, while an image watermark carries an uploaded logo or stamp. Text suits a status, an image suits a brand.

Opacity and Rotation

An opacity from faint to solid decides how much shows through, and a rotation sets the mark upright or on a diagonal so it does not follow the text lines.

Position or Tile

The mark sits where it is placed, whether a corner for subtle branding or the center for a stamp. It can also tile across the page so cropping it away takes the content too.

Every Page or a Range

A watermark covers the whole document or only the pages picked, so a cover can stay clean while the body pages carry the label.

Adding a watermark, stamping a document and applying an overlay all name the same action. This tool draws the mark into a new copy and leaves the source file untouched.

Honest comparison

In the Browser vs a Hosted Marker

Both stamp a label or a logo onto a PDF. The difference is where the file goes and how many can be done at once.

Point of comparison This tool Marked in the browser Stamped on the device Hosted markers Uploaded and stamped on a server
Where the file goes Held on the device Sent off to a server
Text and image marks Both, with a preview Usually both
A mark of their own added Never, only the mark set Some stamp a free-tier tag
Whole libraries at once One file in the browser Batch on their hardware
Lock it right after A separate step Often chained in one flow

Those two rows at the bottom are where a hosted service earns its upload. Marking a whole library at once fits a server, and a hosted suite can stamp then lock in a single pass. Everywhere else the browser wins, and the document stays on the machine.

Why no upload

The PDF Never Leaves the Device

Drawing a label onto a page is a small edit the browser makes on the file it already holds. There is no processing that needs a server, so the mark is added on the device with nothing sent out.

The file is never received, so there is no stored copy to guard and no retention policy to take on trust. A contract stamped as CONFIDENTIAL never has to leave the machine to earn the label.

1. Turn on the developer tools and switch to the Network tab
2. Wipe the current entries and let it keep logging
3. Add a watermark with the panel above
Nothing appears. The mark was drawn inside the tab that had the file.
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Reference

What Goes Into a Watermark

A watermark is a set of choices about what the mark says and how it sits on the page. These are the controls behind it.

SettingRangeWhat it decides
Typetext or imageA typed label carries a status or a name. An uploaded PNG or JPG carries a logo, a stamp or a signature mark.
Opacityfaint to solidHow much of the mark shows through. A low value keeps body text readable, while a high value makes the mark the first thing seen.
Rotationany angleThe tilt of the mark. A diagonal near forty-five degrees is the classic stamp and avoids lining up with the text.
Positionnine points or customWhere the mark sits. A center placement covers the most area, and a corner is subtler but easier to crop off.
Tilesingle or repeatedOne mark, or the mark repeated in a grid across the page, sometimes called a mosaic, so it survives a crop and reads as deliberate.
Layerover or behindThe mark drawn on top of the content, or behind it so the text stays crisp and fully readable on top.
Pagesall or a rangeEvery page, or only the pages picked such as the odd or even set or a custom range, so sensitive pages carry the label and a cover can stay clean.
Text fontsbase PDF fontsHelvetica, Times and Courier render the same everywhere, since they are the standard fonts a PDF reader always has.
Flattenbakes the mark inFlattening merges the mark into the page as fixed content, which drops the separate layer and makes the watermark harder to strip. It is a one-way step.
File sizetext tiny, image moreA text mark adds a few kilobytes. A logo adds more, from roughly fifty to two hundred kilobytes for one image.

A Label, Not a Lock

A watermark is drawn onto the page as ordinary content. It states a status, carries a brand and deters casual reuse, but it does not encrypt anything. A determined reader can crop or strip a mark, which is why a tile is harder to remove than a corner. It is also why a document that must stay shut needs a password as well. The standards below define the page content a mark is drawn into.

Alternatives

Other Ways to Watermark a PDF

Each of these stamps a page. They differ in the control they offer and whether they run on the device.

Adobe Acrobat

Edit then Watermark then Add opens a panel for text or an image mark.
Opacity, rotation and position are all set there, with a preview.
The watermark controls sit behind the paid tier of Acrobat.

LibreOffice Draw

Open the PDF in Draw and place a text box or an image on the page.
Set the transparency and export the page back to PDF.
The mark is added page by page, which is slow across a long document.

Command Line, pdftk or qpdf

A stamp file holds the mark, then pdftk or qpdf overlays it on each page.
It is scriptable, which suits repeating one stamp over many files.
The mark has to be built as a separate PDF first, and it installs software.

macOS, in Preview

The markup tools add a text box or a shape onto a page.
It works for a quick one-page label rather than a full stamp.
There is no true watermark feature, so it does not tile or set opacity well.

Each of these keeps the file on the computer it opened on, apart from hosted markers that ask for an upload. The tool above does the same.

Before marking

Three Things to Get Right on a Watermark

A watermark is easy to overdo or to make pointless. These three keep it useful.

Keep the Opacity Low

A mark around twenty to thirty percent opacity reads clearly while the text underneath stays legible. Push it much higher and the watermark starts to fight the content it sits on.

Place It Where It Counts

A corner mark is subtle but simple to crop away. A centered diagonal, or a tile across the page, covers the content and is far harder to remove without taking the page with it.

A Mark Is Not Security

A watermark labels and deters, but it can be removed by someone set on it. When a file truly must be protected, add a password as well so the content cannot be opened or copied freely.

The desktop edition

When Every File Needs the Same Stamp

The browser tool marks one document at a time, held in memory. A library of contracts, or a batch where each file carries a name for tracking, is work for the desktop edition, which reads from disk and stamps every file without a tab open.

In a browser tabone file at a time, held in memory
On the desktopa whole folder stamped in one pass
Whole Folders

Point it at a directory and every PDF inside is stamped with the same text or logo in one pass.

A Name Per File

Each copy can carry a recipient name or a date, which marks who a document was sent to for tracking.

Repeatable

A saved stamp marks a folder on a schedule, which suits a set of documents that goes out each week.

Common questions

Add Watermark Questions

Either a text label or an image. Text suits a status or a name, such as DRAFT, CONFIDENTIAL, SAMPLE or a date, with a font, a size and a color set for it. An image suits a logo, a stamp or a signature mark, uploaded as a PNG or a JPG and scaled to fit the page.
No. A watermark is a label drawn on the page, not a lock. It states a status, carries a brand and deters casual reuse, but the content underneath is still open. A document that must stay shut needs a password as well, which can be added with the PDF locker tool.
By someone set on it, yes. A corner mark is the easiest to crop away, while a centered diagonal or a tiled mark is much harder to strip without losing the content around it. Flattening the mark into the page makes it harder still to lift out. A watermark raises the effort to reuse a document rather than making it impossible.
Not at a sensible opacity. A mark around twenty to thirty percent shows clearly while the body text stays readable through it. Drawing the mark behind the content instead of over it keeps the text fully crisp on top.
Yes. A rotation near forty-five degrees is the classic stamp look. The diagonal covers more of the page and does not line up with the text, which makes it read as an intentional mark rather than part of the document.
Yes. A tile option repeats the mark in a grid over the whole page. That keeps a SAMPLE or a copyright label visible even if a page is cropped, since removing the mark would remove the content with it.
Yes. A page range, or an odd or even selection, limits the watermark to the pages picked, so the sensitive pages carry the label while a cover or an index page can be left clean. The mark otherwise applies to every page at once.
No. The tool draws the mark into a new copy and downloads that, leaving the source file exactly as it was. A clean master is always kept, which matters when the same document is stamped different ways for different recipients.
No. Drawing a label onto a page is an edit the browser makes on the device. This site has no upload address, so the file has nowhere to go and no server sees it. The Network panel in the developer tools stays empty while a mark is applied.
A text mark adds only a few kilobytes across the whole file. An image adds more, roughly fifty to two hundred kilobytes for one logo, since the picture itself is stored once and reused on each page.
The standard PDF fonts, Helvetica, Times and Courier, which every reader has built in. Using them means the watermark renders the same on any device without a font needing to travel with the file.
Yes, a phone browser handles it with nothing to install. Marking a document CONFIDENTIAL before forwarding it is quick on mobile. Lining up a logo across a long file is easier on a bigger screen.
Any modern browser runs it, across desktops, laptops, tablets and phones alike. There is nothing to download and no extension to enable.
No. The only mark on the page is the one set here. The tool adds no branding of its own, no page counter and no paywall, so the watermarked file carries the label wanted and nothing else.
Serving a static page costs little when the browser does the marking, and no file is received to store. The paid desktop edition, used for folder-scale and recurring stamping, is what keeps the browser tools free.

OnlinePCApps Documents Group

Written and reviewed by Marcus Vance, who has worked on PDF page content and document branding here since 2013

Last reviewed August 2026
13
Years on file formats
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Files uploaded
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A watermark is not a special feature of a PDF so much as ordinary page content used with intent. The tool draws text or an image onto each page at the opacity and angle set, either over the existing content or behind it. Because it is drawn content, it renders anywhere a PDF opens. And because it is only content, it can be cropped or stripped by someone determined, which is the honest limit of any watermark. On this page the mark is drawn in JavaScript on the device page by page, then written into a new file with nothing sent to a server.

Specifications followed

ISO 32000 · Page content Text and image marks Opacity and rotation Base PDF fonts
Built on the same shared design system as every OnlinePCApps tool. onlinepcapps.com

Add a Watermark to a PDF

Free, no sign-up and no upload. The mark is drawn on the device and the original file is left untouched.

Add a Watermark Free, no account Try Desktop Edition For folders and faster batches
Add a Watermark