You add a per-viewer watermark to a PDF by sharing it through a link, not by editing the file yourself: every share is watermarked by default. Each viewer sees their own email address and the date laid across the page as they read, so the watermark is different for every person even though the underlying document is the same. It is on every plan, and it appears on screen, not on downloaded copies.
Steps to add a per-viewer watermark
- Upload the PDF into a [room](/glossary/virtual-data-room/) on any plan, since the watermark is on by default on Free, Plus, Pro and Business.
- Open Share on the document or room and leave "Protection for viewers" at On, the default, which applies the watermark. On Pro and above a room can be set to start its new shares relaxed, so check the room's settings if the mark is missing.
- Know what the default includes. The watermark shows the viewer's email, a visit code and the date and time (UTC). The same default blanks the document briefly on screenshot shortcuts and turns off printing, right-click, text selection and copying in our viewer; on Pro and above a share can also be strict, blanking whenever the viewer switches tab or window. This adds friction and attribution; it does not prevent a determined leak.
- Make the email on the mark a proven one. Set "Who may open this" to "Anyone who verifies an email address" (verified email, on Plus and above, so included on Pro), so the address on the watermark is one the viewer has proved is theirs.
- Send the link as usual. The watermark applies automatically each time someone opens the document, without you doing anything per recipient.
- Use "Open as a viewer" in the share dialog before sending to a real recipient, and confirm the mark is legible without hiding the text.
Edge cases and what to check
A watermark deters a screenshot from circulating anonymously. It does not stop the screenshot from being taken in the first place. If someone crops the watermark out of the image before forwarding it, the trace is gone, so treat this as a deterrent rather than a lock, a distinction covered in full in deterrence vs prevention: what document security can and cannot do.
A watermark is only as good as the address behind it. If the link only asks for an email address, the one on the page could be made up. Pair the watermark with a verified email, or with an NDA on Pro and Business, so the person opening the file has proved the address is theirs. The watermark is applied on screen; a downloaded copy does not carry it, so set Downloads to Off, available on every plan, where attribution must hold.
The per-viewer watermark is on every plan, by default. NDA gating is on Pro and Business. Free and Plus include access controls (an email address on Free; verified email, passcodes and expiry from Plus), and Plus adds page-by-page analytics. Weigh whether the sensitivity of the document justifies an upgrade for those.
Once the link is live, check three things. First, that the watermark text is legible without covering the content underneath it. Second, that it appears for every viewer, not just the first one who opens the link. Third, that the document's Activity tab shows the same email addresses that appear on the mark, the same verified-identity idea covered in visits vs verified readers.
If your current tool cannot do this
Plenty of tools offer a static watermark reading "confidential" or your company name, which decorates the page but proves nothing about who leaked it. Judge a watermarking feature against these questions before relying on it.
- Does the watermark change per viewer, or is it the same image for everyone who opens the link?
- Is the identity on the watermark tied to a verified viewer, or could anyone type in any name?
- Does the platform apply the watermark automatically, or does it require you to generate a separate file for every recipient by hand?
A tool that marks each view with a per-person identity automatically, without extra manual work on your side, clears this bar. 99 Data Rooms does this by default on every plan, and what does document watermarking actually stop explains the honest limits of what a watermark can and cannot prevent. Our roundup of best document watermarking tools in 2026 compares this against other vendors, and how you trace a leaked document back to its source covers what to do once a watermark has actually flagged a leak.
Generic watermark vs per-viewer watermark
| Generic watermark | Per-viewer watermark | |
|---|---|---|
| What it shows | The same text for every viewer | That viewer's email address and the date |
| Traces a leaked screenshot | No | Points a screenshot back to the address that opened it, unless the mark is cropped out or the screen is photographed |
| Deters careless sharing | Weakly | More strongly, since an address is attached |
| Setup effort per recipient | None, or manual per file | None, applied automatically per view |
The difference is entirely in whether the mark is unique to the person looking at it. A generic stamp is decoration. A per-viewer stamp names the viewer.
Frequently asked questions
What does the per-viewer watermark show? On 99 Data Rooms the mark carries the viewer's email address and the date. It does not include their IP address. The goal is enough identifying detail that a screenshot points at one specific address, not a vague warning.
Can someone remove the watermark before sharing a screenshot? It can be cropped or edited out with enough effort, especially from a still image. Treat watermarking as a deterrent that raises the cost of leaking, not an unbreakable lock on the content.
Does the watermark work without verifying the viewer? It does, but the address on the mark is only as trustworthy as how the viewer was identified. Pairing it with a verified email means the address on the page is one the viewer proved is theirs, not one they typed in freely.
What plan do I need for the per-viewer watermark? Any plan. It is on by default on Free, Plus, Pro and Business, and you can relax it for one share. NDA gating is on Pro and Business.
Does the watermark appear on a downloaded copy? No. It is shown on screen as the viewer reads. A downloaded copy does not carry it, so set Downloads to Off on the link, on any plan, if attribution must hold.
Make a screenshot attributable
Share your next sensitive PDF with the watermark on, as it is by default, ask for a verified email so the address behind it is real, and make a screenshot attributable to the address that opened it. See pricing for what each plan includes, or start free to try it first.
Many leaks happen because nobody expected the document to travel past its first reader. A watermark does not stop that first person from taking a photo of their screen, but it changes the calculation, since their email address is now visible across whatever they forward. That single visible detail can be enough to make someone think twice before passing a sensitive page further along than it was ever meant to go.
Sources
- Watermark behaviour, plan availability and access-setting combinations reflect 99 Data Rooms product facts. General claims about generic static watermarks describe common industry practice, not any single named vendor.