Free PDF Stamper
Free PDF Stamping Tool — Add Signatures & Watermarks Online
Stamp any PDF with your signature, watermark, or approval mark — entirely in your browser. No uploads, no software, no account needed.
PDF Stamping Tool
Add signatures, watermarks, or logo stamps to any PDF — visually, in your browser.
1. Upload your PDF
Select the document you want to stamp.
2. Upload your stamp
PNG with transparency works best.
2b. Stamp opacity
Adjust how transparent the stamp appears on the document.
3. Choose pages
Select which pages to stamp.
4. Generate
Stamps everything client-side. Nothing is uploaded.
How to stamp a PDF in 4 simple steps
This tool runs entirely in your browser. Your files never leave your device, which makes it ideal for signing contracts, certifying invoices, watermarking proposals, and approving deliverables that contain sensitive information.
Upload the PDF
Click the upload card or drag your document onto it. The first page renders instantly so you can begin positioning.
Upload your stamp image
Click the upload card or drag your stamp image onto it. A transparent PNG looks most professional. Common examples include scanned signatures, "Paid" marks, company seals, draft watermarks, or approval logos.
Position, resize, & adjust Opacity
Drag the blue dashed box anywhere on the page. The corner handle lets you scale the stamp up or down. Use the navigation buttons to preview each page. Slide the Stamp Opacity slider to adjust the opacity of the stamp.
Choose pages & download
Apply the stamp to only the current page, every page, or a custom selection — then click Generate to download the finished PDF.
Common use cases
A few scenarios where this tool saves time compared to opening a desktop editor.
- Adding a scanned signature to a freelance contract
- Marking invoices as "Paid", "Approved" or "Void"
- Applying a corporate logo to outgoing proposals
- Watermarking draft PDFs before sharing with clients
- Adding a notary or certification seal to legal documents
- Branding training materials and internal handbooks
- Confidentiality stamps on sensitive reports
Tips for the best results
A few small choices can make your stamped PDFs look much more professional.
- Use a PNG image with a transparent background so the stamp blends with the document
- Keep stamp images at least 600 pixels wide to avoid blurriness when scaled up
- For signatures, scan at 300 DPI on a plain white sheet and remove the background before uploading
- When stamping every page of a long document, place the stamp in an area that does not collide with body text — corners and margins work well
- Preview each affected page before downloading — the visual placement on the active page is applied identically to all selected pages, using relative coordinates
- Use the opacity slider to control stamp transparency — lower values work well for watermarks, higher values for signatures
Keyboard shortcuts
Speed up your workflow with these built-in shortcuts.
- Left Arrow — go to the previous page
- Right Arrow — go to the next page
- Ctrl+Enter (or Cmd+Enter on Mac) — generate the stamped PDF
Shortcuts are disabled while you are typing in an input field.
Is this tool really free?
Yes. The tool is provided free of charge and runs entirely in your web browser. There are no hidden limits on how many times you can use the tool, no watermarks added to your output.
Do I have to create an account?
No you don't have to create an account. You are only required to provide your email so that I can send you news about product updates and features.
Are my files uploaded anywhere?
No. All processing happens locally on your device using JavaScript libraries loaded in your browser. Your PDF and stamp image never travel across the internet, which is why the tool also works offline once the page is loaded.
What file types are supported?
The tool accepts standard PDF documents and accepts PNG or JPG images as the stamp. PNG with transparency is recommended for the cleanest look, especially for signatures and logos.
Can I stamp every page at once?
Yes. In the page selection step, choose "All pages" and the same stamp will be applied to every page using the position and size you set in the preview. You can also pick a custom subset of pages.
Will the stamped PDF still be searchable?
Yes. The original PDF content — including selectable text, links, and form fields — is preserved. The stamp is added as an image layer on top, so existing text underneath is not damaged.
Is there a maximum file size?
There is a maximum filesize limit of 100 MB for the PDF file and 5 MB for the stamp image in the free tier.
Can I use this for legally binding signatures?
A visual stamp is sufficient for many everyday business documents, but legally binding e-signatures often require certificate-based digital signatures and an auditable trail. If you need that level of assurance, use a dedicated e-signature service in addition to a visual mark.
Does it work on mobile?
Yes. The interface adapts to smaller screens and supports touch dragging. For complex documents with many pages, a desktop browser is more comfortable.
About this PDF stamper
A lightweight, privacy-first utility for adding signatures, watermarks, approval marks, and brand seals to PDF documents — without uploading anything to a server.
PDFs power a huge portion of the world's business communication. Contracts, invoices, expense reports, design proofs, and onboarding paperwork all rely on the format. Yet the moment someone needs to add a signature or an "Approved" mark, the workflow often breaks down. People print the document, sign it by hand, scan it back, and email it on. That cycle is slow, wasteful, and easy to interrupt.
This tool exists to close that gap. By keeping the entire workflow inside your browser, it offers three practical benefits:
- Confidential documents never leave your computer, which matters for legal, medical, and financial files
- There is no software to install — open the page and start working immediately on any modern device
- Processing is fast because no network round-trip is required, and it continues to work without an internet connection once loaded
Under the hood the tool uses two well-tested open-source libraries: one for rendering each page of your PDF to a preview canvas, and another for embedding your stamp into a freshly generated copy of the document. Together they preserve every original element of the file — selectable text, hyperlinks, form fields, and metadata — while layering the new image on top.
Privacy & security
A short summary of how your data is handled while you use this tool.
- No file you select is uploaded to any server
- No cookies are required for the core stamping workflow
- No tracking pixels are embedded in the generated PDF
- The page can be saved offline and reopened later
Compatibility
Works in any modern desktop or mobile browser, including:
- Google Chrome 90 and newer
- Mozilla Firefox 88 and newer
- Apple Safari 14 and newer
- Microsoft Edge 90 and newer
Why use this PDF stamper?
- Private & secure — your PDF and stamp image never leave your device
- No installation required — works in any modern browser, on desktop or mobile
- Fully featured — drag-to-position, resize, opacity control, multi-page support
- Completely free — no watermarks, no file limits, no hidden paywalls
How it works
Upload your PDF, upload your stamp image, drag it into position, and generate. The stamp is embedded as an image layer on top of your original PDF — all existing text, links, and form fields remain intact and fully searchable.
Use Cases
This tool is commonly used for: signing freelance contracts, marking invoices as paid, applying company logos to proposals, watermarking draft documents, adding notary seals, and branding training materials.