PDF Watermark

Five steps, none of which involve an upload.

1. 1

   Open your PDF

   Drop the document onto the page or browse for it. Every page appears straight away, and nothing is uploaded anywhere.

2. 2

   Choose text or a logo

   Type the words you want stamped, or pick an image file to use as the mark. A preset gets you a finished CONFIDENTIAL or DRAFT stamp in one click.

3. 3

   Place it

   Pick one of nine positions, drag the mark anywhere on the page, or switch to tiled to repeat it across the whole sheet. Set the angle, the size and how strong the ink is.

4. 4

   Choose the pages

   Mark every page, only the odd or even ones, a range such as 2-8, or skip the cover. The preview shows exactly which pages will be marked.

5. 5

   Download

   Press Add watermark and save the finished PDF. The original file on your device is never changed.

A watermark answers a question the reader would otherwise have to ask someone: is this the final version, may I forward it, and who does it belong to? It travels with the file, survives being emailed on, and is visible in every viewer and on every printout — which is more than can be said for a note in the covering email or a property field nobody opens.

Benefits of PDF Watermarking

• Ownership: a company name or logo on every sheet makes the source obvious in a screenshot, a photocopy and a forwarded attachment alike.
• Status: DRAFT, SAMPLE and CONFIDENTIAL stop a working version being read as a final one, which is the single most common reason people reach for this tool.
• Deterrence: a diagonal mark across the middle of the page makes casual reuse obvious without making the document unreadable.
• Traceability: a recipient's name in the mark turns a leaked PDF into a traceable one, one copy per recipient.
• No round trip: the document is read, marked and saved on your own machine, so a contract under embargo never touches a server.

The two kinds of mark solve different problems and the controls differ accordingly. A text mark is set live in one of the standard PDF typefaces, so it adds nothing to the file size and stays real, selectable text in the finished document. A logo mark embeds a picture, which is the only way to carry a brand, a signature or a seal.

Watermark Types

• Text watermark: words such as CONFIDENTIAL or DRAFT, in Helvetica, Times or Courier, in four styles, in any colour, with an optional outline.
• Image watermark: a company logo, a scanned signature or a seal, with its transparency preserved and its proportions kept.
• Drag placement: nine snap positions to start from, then drag the mark anywhere on the page and it stays there on every marked sheet.
• Outline: a stroked edge in a second colour, which is what keeps a pale mark legible over a dark photograph.
• Ink strength: a continuous 5 to 100 per cent, so the same mark can be a faint tint or a hard stamp.

Which Logo Files Work

PNG, JPEG, WebP, GIF, BMP and SVG are all accepted, and every one of them is decoded on your device and converted to a form the PDF format can carry. Transparency in a PNG, a GIF or an SVG is kept, so a logo on a transparent background does not arrive sitting on a white rectangle. A photo taken on a phone carries its orientation as a tag rather than in the pixels, and that tag is applied, so a signature photographed in portrait does not go into the document on its side. An SVG that declares only a viewBox is rasterised at the size that viewBox describes — the case where naive tools draw nothing at all.

Placement is the part of a watermarking tool that is easy to get almost right. The mark has a position, an angle and a size, and all three interact: a mark that fits the page perfectly at zero degrees needs about forty per cent more room once it is turned to forty-five, which is why the size control's own upper bound moves when you move the angle.

Nine Positions, or Anywhere

• The nine anchors: the four corners, the middle of each edge, and the centre — the grid every competitor offers.
• Margins: small, medium or large, being 24, 36 and 54 points from the paper edge. The margin is a guarantee: a mark that cannot honour it is reported rather than quietly pushed against the edge.
• Drag: press the mark in the preview and move it. The offset is kept as a distance from the anchor, so it survives a change of page size.
• Relative size: express the size as a percentage of the page width and one setting reads the same on a business card and on a poster.

Tiled and Diagonal

Switching the layout to tiled repeats the mark in an even lattice across the whole sheet, at whatever angle is set — the pattern people mean when they ask for a mosaic or a repeated watermark. The lattice is centred on the page rather than started from a corner, so it stays symmetric on any paper size and under any rotation, and the spacing control sets how much air sits between tiles. Tiles whose centre would fall off the sheet are left out rather than pushed back onto the edge, which is what stops the last row and column piling up on top of their neighbours.

Rotated and Cropped Pages

A PDF page has a stored size and, separately, a rotation flag that the viewer applies before drawing it — which is how a scanned page gets straightened without its pixels being touched. It can also carry a crop box that hides part of the stored sheet. Both are honoured here: the mark is placed against the page as it is displayed, so the top-right corner is the visible top-right on all four quarter turns, and nothing is ever written into the strip a viewer clips away. Tools that skip this put a corner stamp along the side of every straightened scan and a diagonal across the wrong axis.

A PDF page is a list of drawing instructions. Adding a watermark means adding more instructions to that list — which is why the finished document stays a real PDF rather than becoming a picture of one, and why the original text remains selectable and searchable underneath.

Behind or In Front of the Content

Where the new instructions go in the list decides everything about how the result reads. Put them at the end and the mark is drawn last, over the top of the page: unmissable, and it obscures whatever it crosses. Put them at the start and the page's own content is drawn over the mark instead, so the mark shows through only where the page is blank. That second arrangement is what most people actually mean by a watermark, and it is why the layer control exists. A tool that can only append can only ever produce a stamp.

Opacity and Legibility

Ink strength and layer solve overlapping problems and are worth setting together. A mark behind the content can be strong without hurting readability, because nothing important is on top of it. A mark in front has to be faint enough to read through — around fifteen to thirty per cent for a full-page diagonal — unless it is small and tucked into a margin, where sixty per cent and up is comfortable. The control stops at five per cent because below that the difference from blank paper is not something a reader or a printer can be relied on to render.

The document is read on your device, the mark is placed against every page's own visible box, and a new file is written. Nothing is uploaded, and the file you started with is not modified — the result is a new document you choose where to save.

Watermarking Process

• Read: every page's visible box and rotation flag are read from the document's structure, with nothing rendered and nothing sent anywhere.
• Fit: the largest size the mark can take at the chosen angle and margin is worked out per page, and the size control's own range follows it.
• Place: the mark's centre is decided on the page as the reader sees it, then mapped back into the coordinates the file stores.
• Draw: the drawing instructions are written into their own layer, placed before or after the page's own content as the layer setting says.
• Save: a new document is assembled and handed to you. The work runs off the main thread, so the page stays responsive and can be cancelled mid-run.

Fonts and Languages

Helvetica, Times and Courier are built into the PDF format itself, so a text mark in any of them adds no font data to your document at all. They cover Latin-1 — most Western European languages. When the words you type need something they cannot set, such as Cyrillic or Greek, a Unicode face served from this site is embedded instead, subset to only the characters you used. No font is ever fetched from anywhere else. Scripts no available face covers, such as Chinese or Hebrew, are named in a clear message rather than drawn as a row of empty boxes — a mark made of blank rectangles looks like a tool that worked.

Marking a hundred-page document takes about a quarter of a second, and none of it leaves your device.

The settings that matter are different for each job, and the presets exist because five combinations cover most of what people arrive wanting.

Common Use Cases

• Confidential: a red diagonal across the centre at about a quarter strength, in front of the content, so it is unmissable without hiding anything.
• Draft: the same shape in amber, slightly stronger, usually on every page including the cover.
• Company logo: a small mark in a bottom corner at high strength, behind the content, on every page after the cover.
• Do not copy: tiled at a shallow angle and low strength, which covers the whole sheet without making a word of it hard to read.
• Per-recipient: a name and a date in a footer corner, one pass per recipient, which turns a leak into something traceable.

Print, Screen, or Both

A mark drawn into the page appears everywhere by default, which is normally right. The two exceptions have their own setting. Print only puts a DRAFT stamp on every sheet that comes out of a printer while leaving the on-screen copy clean — useful when the same file is both a working document and a review copy. Screen only does the reverse, for a mark meant to discourage screenshots of a file that is expected to be printed cleanly. Both are stored using the PDF format's own optional-content mechanism, and readers that do not implement it show the mark rather than hiding it, so nothing ever disappears by accident.

• PDF compressor
• PDF merger
• PDF splitter
• PDF page numbers
• Rotate PDF pages
• Image watermark