Stamp your PDF once per buyer — automatically.
Upload one master PDF and your buyer list. BatchStamp generates a separate, watermarked copy for every customer, each carrying a hidden trace code, so a leaked file can be traced back to the buyer who shared it. No uploads, no accounts, no per-file busywork.
- 1Upload the master PDFThe file you sell to every customer.
- 2Paste the buyer listOne per line:
Name,email. CSV paste works too. - 3Download the ZIPOne watermarked PDF per buyer, ready to send.
1 · Master PDF
PDF only
2 · Buyer list
3 · Options
{name} {email} {index} {code} {date}Output
Why the hidden code matters
Every copy carries a unique code such as BS-03-1A9F2C, stored both as visible metadata and as invisible text inside the page content. If a copy shows up on a piracy site, run the file through any text extractor and the code tells you exactly which buyer received it — so you can warn or claim, instead of guessing.
| Field | What happens |
|---|---|
| Title / Subject | Set to the buyer name |
| Keywords | Trace code + buyer email |
| Hidden text | Trace code at zero opacity on every page |
Simple, honest pricing
Free trial
- Up to 5 buyers per file
- All watermark positions
- Runs fully in your browser
Launch license
- Unlimited buyers
- Hidden trace codes
- CSV import, ZIP export
- Free updates for 12 months
Pro (subscription)
- Everything in Launch
- Stamp from a saved list
- Priority feature requests
- Cancel anytime
Questions
Are my files uploaded to a server?
No. All processing happens in your browser using PDF-Lib. Your PDF never leaves your device, which also means your buyers' data stays yours.
What happens to non-Latin characters in names?
Standard PDF fonts only cover Latin characters, so names in Chinese, Japanese or Arabic are reduced to their Latin part automatically; if nothing is left, the watermark falls back to Buyer N. The hidden trace code always stays intact because it is pure ASCII.
Can a buyer remove the watermark?
The visible watermark can be cropped or covered. That is why every copy also carries an invisible trace code — removing the visible mark does not remove the evidence.
Does this replace a full DRM platform?
No, and it should not pretend to. Light-weight protection combined with download limits and expiring links is the practical setup for small digital products; heavy DRM usually annoys paying customers more than it stops sharing.