Encrypt PDF

Protect a PDF with a user password (AES-256).

Free on the API and MCP server — generous limits, files deleted within an hour, content never logged.

🖥️

This one runs on our servers — under the same privacy rules.
Files are virus-scanned before processing, stored encrypted, and deleted within 1 hour. Content is never logged. And it's free: 250 operations a day, every day, plus burst on spare capacity.

Encrypt PDF needs server-grade machinery (heavy conversion, OCR or cryptography the browser can't do safely), so it runs through the REST API and the MCP server instead of an uploader. One free key drives both — get yours in about a minute.

REST API

curl -X POST https://api.pdfmcp.org/v1/jobs \
  -H "X-API-Key: pdfmcp_live_YOUR_KEY" \
  -F files=@your-file.pdf -F op=encrypt -F password=... -F owner_password=...

Submit → poll → download. Full walkthrough in the REST API quickstart guide.

MCP (for AI agents)

{
  "mcpServers": {
    "pdfmcp": {
      "url": "https://mcp.pdfmcp.org/mcp",
      "headers": {
        "X-API-Key": "pdfmcp_live_YOUR_KEY"
      }
    }
  }
}

Paste into Claude, Cursor, VS Code, ChatGPT and 9 more clients — setup guides for every major MCP client.

By using the API or MCP server you agree to the Terms of Service and Acceptable Use Policy. Files you send are deleted within an hour; see the Privacy Policy.

How encrypt pdf works here

Protect a PDF with a user password (AES-256). Server-side, the job passes the security inspection gauntlet first (antivirus, structural and active-content checks), runs in a sandboxed worker, and the result waits for you for exactly one hour.

People often pair this with unlock pdf and strip ai metadata & provenance — same deal there: free, private, no sign-up.

Parameters

Parameter	Type		Default	Description
`password`	string	required	—
`owner_password`	string	optional	—

FAQ

Is Encrypt PDF free?

Yes — completely free, with no watermark, no sign-up and no trial clock. On the API/MCP side every key gets 250 guaranteed operations a day plus unlimited burst operations on spare capacity. See the pricing page for the full (short) policy.

What happens to my file?

You send it to the pdfmcp API/MCP server over HTTPS. It is virus-scanned and inspected before processing, stored in an encrypted temporary volume, and automatically deleted within 1 hour of the job finishing. We never log file content or file names.

Can I automate Encrypt PDF with an AI agent or code?

Yes — the exact same operation is a tool on the pdfmcp MCP server (for Claude, Cursor, ChatGPT and other agents) and an endpoint on the REST API. One free key works for both; the guides walk you through setup in about a minute.

Are there limits?

Files up to 100 MB and 500 pages. Web tools are additionally bounded by your device's memory. The caps exist to stop abuse and keep the shared machine fair — they are not a paywall, and there is no paid tier to unlock.

Related tools

Unlock PDF API · MCPRemove password protection (the current password is required).Strip AI metadata & provenance On-deviceRemove AI-generation provenance and identifying metadata from a PDF or image (JPEG/PNG/WebP): C2PA Content Credentials, XMP/EXIF/IPTC AI markers (incl. IPTC DigitalSourceType trainedAlgorithmicMedia), generator Software/Creator tags, EXIF GPS and device data. Metadata only — content and pixels are never modified, image pixels are not re-encoded, and pixel-embedded invisible watermarks (e.g. SynthID) are NOT removed: they live in the image data itself, not in metadata. The result reports exactly what was found and removed, by category.Sanitize PDF On-deviceStrip metadata (incl. XMP), JavaScript, embedded files/attachments, document actions and link/file actions — the safe-to-share version of a PDF.Sign PDF (visual signature) On-devicePlace a visual signature on a PDF: upload the signature image as the SECOND file, or let the signer name be typeset. A self-signed certificate (SHA-256 fingerprint) is generated and recorded in the document metadata. This is an electronic signature stamp + certificate record — not a qualified/PKI document signature.Set PDF permissions API · MCPEncrypt a PDF with an owner password and fine-grained permissions (print, copy, modify, annotate, ...).Redact PDF API · MCPTRUE redaction: content under the regions is removed from the file (not just covered). Modes: explicit regions, literal texts, and/or PII patterns (emails, SSNs, payment-card numbers — Luhn-checked).

Browse the protect & sign hub or the full tool index. Building something bigger? Read the features tour and the free usage policy.