Add watermark to PDF online: text or image, fully customisable

Stamp any PDF with a text or image watermark using the watermark PDF tool at ToolHQ. Customise the text content, font, size, colour, opacity, position, and rotation, and apply it to all pages in seconds. Your file never leaves your device.

A PDF watermark is a semi-transparent text or image overlay placed on top of each page to mark the document's status, ownership, or distribution restriction. Common watermarks include "DRAFT," "CONFIDENTIAL," "COPY," "DO NOT DISTRIBUTE," a company name, or a logo.

Watermarks serve two key purposes: they communicate clearly to anyone who reads the document that it has a specific status or restriction, and they make it harder to pass off a document as something it is not. A clear "DRAFT" watermark on a contract prevents early versions from being mistaken for final, signed copies.

Key Takeaways

• Add text or image watermarks to all pages of a PDF with a single click
• Customise text content, font, size, colour, opacity, position, and rotation angle
• Common uses: DRAFT marks, CONFIDENTIAL stamps, copyright notices, branding
• Watermark is added as an overlay layer, use "Flatten PDF" afterward to make it permanent
• Your file never leaves your device

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What PDF watermarks are and how they work

The PDF standard supports content on multiple layers within a page. Watermarks are typically added as a content stream above the main page content, with reduced opacity so the original content remains visible underneath. The watermark element can be text drawn at a specific rotation, font, and colour, or an image placed at a specific position on the page.

The concept of digital watermarking extends to all types of digital media, but PDF watermarks in the context of this tool are visual overlays, not steganographic marks embedded in the data. They are visible to anyone who views the document and serve as a clear human-readable signal.

ToolHQ's watermark PDF tool adds the watermark as an overlay to every page of your PDF directly in your browser. Your file never leaves your device. If you want the watermark to become a permanent, irremovable part of the document content, use ToolHQ's flatten PDF tool on the result afterward.

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When you need to add a watermark to a PDF

Marking draft documents: Add a diagonal "DRAFT" text watermark before distributing a document for review. This prevents reviewers from using the draft as a final version.

Marking confidential content: A "CONFIDENTIAL" watermark signals handling restrictions to everyone who receives the file, and discourages casual forwarding.

Copyright and ownership marking: Add your company name, website URL, or copyright notice to documents you create before sharing them publicly. This establishes ownership and provides a point of contact.

Distribution control: Mark copies sent to specific recipients with their name or organisation, so if a document leaks, the source can be identified.

Proof and preview documents: Designers and photographers add watermarks to proof documents to prevent clients from using them before final payment.

Internal circulation marking: Add "INTERNAL USE ONLY" or "NOT FOR EXTERNAL DISTRIBUTION" to employee documents, policy files, or unreleased product information.

Mini-story: A law firm created a template library of contract documents and wanted to prevent junior associates from accidentally using template drafts as final contracts. They used ToolHQ's watermark PDF tool to add a diagonal red "DRAFT TEMPLATE" watermark at 30% opacity to all template files. Associates could still read through the documents clearly, but the watermark made it immediately obvious that any given file was not a final version ready to send to clients.

Add a watermark to your PDF now at ToolHQ's watermark PDF tool.

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How to add a watermark to a PDF step by step

1. Open the tool. Visit ToolHQ's watermark PDF tool.
2. Upload your PDF. Drag and drop or click to select the file. Your file stays in your browser and is never sent to any server.
3. Enter your watermark text or select an image. Type the text you want (e.g. "CONFIDENTIAL") or upload an image file (e.g. your company logo) to use as the watermark.
4. Customise the watermark. Set the font, size, colour, and opacity for text watermarks. Set position and opacity for image watermarks. Choose a rotation angle (typically 45 degrees for diagonal watermarks).
5. Apply and download. Click "Add Watermark". The tool applies the watermark to every page and generates a new PDF. Download and verify the watermark appears as expected.

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Watermark customisation reference

Use this table to decide on the right settings for common watermark types.

Watermark type	Recommended opacity	Position	Rotation
DRAFT (draft review mark)	20–30%	Centre of page	45 degrees diagonal
CONFIDENTIAL	20–30%	Centre of page	45 degrees diagonal
Copyright notice / URL	40–60%	Bottom of page	0 degrees (horizontal)
Company name (branding)	15–25%	Top or bottom	0 degrees
COPY (indicating a copy)	30–40%	Centre of page	45 degrees diagonal
Logo or image watermark	15–25%	Corner or centre	0 degrees

Opacity guide:

• 10–20%: Very subtle; present but barely noticeable
• 20–30%: Standard draft/status marking; visible but not obstructive
• 40–60%: Strong presence; clearly visible across the page content
• 70–100%: Very prominent; may obstruct reading of the underlying content

Mini-story: A photographer was sending a 40-image portfolio PDF to a prospective client for approval. She added her studio's logo as a watermark at 20% opacity in the centre of each page. The client could evaluate the full quality of each image clearly, but using the unwatermarked images without purchasing a licence was no longer possible. After the client approved and paid, she sent the clean, unwatermarked final files.

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Frequently asked questions

Can I add a watermark to only specific pages? Many watermark tools apply the mark to all pages. If you need to watermark only certain pages, extract those pages first, apply the watermark, then merge them back using ToolHQ's PDF merger.

Will the watermark be removed if someone edits the PDF? Watermarks added as overlay layers can potentially be removed by someone with PDF editing software. If permanent watermarking is critical, flatten the watermarked PDF using ToolHQ's flatten PDF tool to embed the watermark into the page content, making it much harder to remove.

What font should I use for text watermarks? Bold, sans-serif fonts (such as Arial, Helvetica, or similar) are easiest to read at low opacity across most document backgrounds. Avoid decorative or script fonts that become illegible when semi-transparent.

Can I add a watermark to a password-protected PDF? If the PDF is locked for editing, you will need to unlock it first using ToolHQ's unlock PDF tool. Once unlocked, adding a watermark works normally.

Does adding a watermark change the file size? Adding a text watermark adds a minimal amount of data to the PDF and has a negligible effect on file size. Adding an image watermark increases the size slightly, proportional to the image file size.

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The short version

Adding a watermark to a PDF takes under a minute with ToolHQ's watermark tool. Type your text (or upload an image), set the opacity and rotation, and download the watermarked PDF with the mark applied to every page. Use it to mark drafts, signal confidentiality, add copyright notices, or brand your documents before sharing. For a permanent, irremovable watermark, flatten the result afterward. Your file never leaves your device throughout the entire process.

The most important setting to get right is opacity. Too high and the watermark obscures the content; too low and it is easy to overlook. For most draft and status marks, 20 to 30% opacity hits the right balance: clearly visible without interfering with the readability of the underlying text. Start there and adjust based on your specific background colour and document style.

Add a watermark to your PDF now at ToolHQ.

Related tools: Watermark adder | Sign PDF | PDF password protect | Remove watermark from PDF