PDF Watermark & Unlock PDF Tool: Stamp Text, Add Page Numbers, Remove a Password

This PDF watermark and unlock PDF tool adds a text or image watermark to many PDFs at once, adds "Page X of Y" page numbers, removes a PDF password when you supply the correct one, and can set a password on a file. Give it links to PDFs, get back direct, signed download links. It is built for bulk work and for use through the API, Make, n8n or Zapier.

This tool cannot crack passwords. It never guesses or brute-forces. To unlock a PDF you must supply the correct password. Use it only on files you own or are allowed to modify.

How to add a watermark to a PDF

1. Paste your PDF links into PDF URLs (one per line).
2. Keep Operation on watermark and set Watermark text, for example CONFIDENTIAL.
3. Adjust font size, color, opacity, rotation, position (center, tiled, corners) and page range. Example: opacity 0.3, rotation 45, position tiled.
4. Run. Each output PDF appears in the dataset with a download link.

To add a logo, fill Watermark image URL (PNG, JPG or WebP; transparent PNGs work well). Text and image can be combined.

How to add page numbers to a PDF

Set Page numbers to footer or header. The default format is Page {page} of {total}; change it, for example to {page}/{total}. Leave the watermark text empty if you only want page numbers.

How to unlock a PDF (remove a PDF password)

1. Set Operation to unlock.
2. Enter the file's password in PDF password. It is stored as a secret and never logged.
3. Run. You get the same PDF without the password.

What unlock does, honestly:

• Password you know: removed when you supply the right one. A wrong password gives a clear error.
• Owner restrictions (the "no printing / no copying" flags): removed only when the file opens without a password.
• Not protected at all: you get status not_protected and are not charged.
• Forgotten password: not supported. This tool cannot crack passwords.

How to remove a PDF password and set a new one

Use protect and give New password. The output is encrypted with AES-256. Combine it with a password for the source if the source is protected too.

Input example

{
  "urls": ["https://www.w3.org/WAI/ER/tests/xhtml/testfiles/resources/pdf/dummy.pdf"],
  "operation": "watermark",
  "watermarkText": "CONFIDENTIAL",
  "position": "tiled",
  "opacity": 0.3,
  "rotation": 45,
  "pageNumbers": "footer"
}

Unlock example: {"urls": ["https://example.com/locked.pdf"], "operation": "unlock", "password": "your-password"}

Output example

One dataset row per output file. Failed files get a row with status: "error" and an error message; one bad link never stops the run.

{
  "sourceUrl": "https://www.w3.org/WAI/ER/tests/xhtml/testfiles/resources/pdf/dummy.pdf",
  "fileName": "dummy-watermarked.pdf",
  "url": "https://api.apify.com/v2/key-value-stores/.../records/000-dummy-watermarked.pdf?signature=...",
  "operation": "watermark",
  "pages": 1,
  "pagesStamped": 1,
  "bytes": 13480,
  "status": "ok"
}

The url is signed, so it downloads without an API token. Files stay in the run's key-value store (or your Output store name) until the store expires.

Use cases

• Stamp DRAFT, CONFIDENTIAL or a customer name on contracts, reports and invoices.
• Brand PDFs with a logo before sharing them.
• Number the pages of merged or exported documents.
• Remove a password from your own archived PDFs so they can be indexed or processed.
• Set a password on documents before sending them.

How much does it cost

Pay per event: $0.008 per output PDF (pdf-processed), no start fee. Unlock on a file with nothing to remove is not charged. Use Max output files to cap spend.

Limits

• Default 50 MB and 500 pages per file (max 200 MB). Larger files are skipped with an error.
• Links must be public and direct. Pages that need a login are not supported.
• Page numbers and watermarks are drawn on top of the page content; scanned pages are stamped but not OCR'd.
• Output of a watermark run is not password protected, even if the source was (you supply its password to open it).
• Built-in fonts cover Latin text; other scripts use DejaVu Sans automatically.

FAQ

Can it remove a PDF password if I forgot it? No. It cannot crack, guess or brute-force passwords. You must supply the correct one.

Can it remove "restrictions" such as no printing or copying? Yes, when the file opens without a user password. Use only on files you own or may modify.

Does the watermark change the original text? No. The watermark is an overlay on each page; text remains selectable.

Can I watermark only some pages? Yes: set Page range, for example 1-3,5, odd or 2-.

Can I put a logo on the PDF? Yes: give a PNG, JPG or WebP link in Watermark image URL.

Is the password logged? No. Password fields are secret inputs and are never written to logs or output.

Related tools

• PDF Merger & Splitter
• PDF Compressor
• PDF to Text & OCR