How to Add a Watermark to Every Page of a PDF

Provide PDF data whose decoded bytes begin with %PDF-, enter 1 to 200 characters, choose an opacity from 0.05 to 1.0, and run the operation. A successful result places gray text around the vertical midpoint of every page over its existing content.

Understand the watermark layout

A PDF watermark helps you place the same visible label throughout a document. You might use a short status such as DRAFT, a review note such as INTERNAL REVIEW, or the default label CONFIDENTIAL. This tool adds the supplied text to every page, making it suitable when the mark should cover the document rather than just its opening page.

The appearance has a defined layout. Gray text is placed around the vertical midpoint of each page and drawn over the content already there. Opacity controls the visual strength of the mark. Before starting, choose wording that remains useful across pages with different designs, and plan to inspect the result because underlying content can affect readability.

Apply the text and opacity

Prepare the source as a PDF. The supplied value must decode to bytes beginning with the PDF signature %PDF-. A different document format does not meet the supported input boundary.
Provide the PDF to the tool. Keep a separate copy of the source if you want to compare the marked pages with the original afterward.
Enter the watermark wording. The starting value is CONFIDENTIAL. Replace it with a label containing 1 to 200 characters, including spaces and punctuation. Examples include DRAFT, INTERNAL REVIEW, and FOR APPROVAL. An empty field or a label longer than 200 characters is rejected before PDF processing.
Set opacity if the default does not fit the page design. The default is 0.3. For a chosen value, enter a number from 0.05 through 1.0. The value is converted to a number and then bounded between those endpoints, so an entry outside that interval should not be treated as an unchanged setting.
Run the operation and examine the result. Check several pages for the selected wording, gray appearance, position around the vertical midpoint, and placement over the existing page content.
If the result is unsuccessful, check the text and document inputs as

Interpret coverage and failures

separate checks. First confirm that the label is neither empty nor overlong. Then confirm that the supplied data decodes to a PDF with the required opening signature. Invalid PDF data and recognized PDF-processing errors can also produce an unsuccessful result, so a valid label does not by itself show that the document can be processed.

A successful result has the shape of a PDF with the supplied wording on every page. The text remains gray, appears around each page's vertical midpoint, and overlays content that was already present. Opacity changes the visual strength of the mark, not its documented page coverage or general position.

Review a title page, a dense text page, and a page containing prominent graphics when those page types are available. The same placement may interact differently with each design. If you need a corner position or a text color other than the documented gray appearance, those controls are outside the behavior described here.

Worked example

A project coordinator needs to mark a 12-page draft PDF for internal review before sharing it with colleagues and chooses a short label with a low supported opacity.

Provide the PDF, enter INTERNAL REVIEW, set opacity to 0.2, and run the operation. Inspect the resulting pages for the wording and documented placement if processing succeeds.

A successful result containing a PDF in which INTERNAL REVIEW appears on every page as gray text around the vertical midpoint over existing content, with the selected opacity applied.

Limitations

The documented appearance uses gray text around the vertical midpoint over existing content; other color and placement controls are not described.
The supplied value must decode to data beginning with %PDF-; formats that do not meet that PDF signature boundary are outside the supported input.

Common errors

A failed operation may reflect separate input problems. Check the label for an empty or overlong value and check the decoded document for the %PDF- signature, then correct the input that fails its own check.

FAQ

Can I watermark every page of a PDF?

When the supplied data meets the PDF boundary and the label passes its length check, the wording is added to every page around the vertical midpoint in gray over existing content.

What opacity should I use for a PDF watermark?

The starting opacity is 0.3. Enter a number from 0.05 through 1.0 for a selected setting; the value is converted to a number and bounded within those limits.

Why did my PDF watermark operation fail?

An empty label or one longer than 200 characters is rejected before PDF processing. Invalid PDF data and recognized PDF-processing errors can also produce an unsuccessful result.