How to add page numbers to a PDF with an API

POST a PDF to /v1/pdf/page-numbers. It returns the PDF with a number stamped on each page in the format you choose, such as Page {n} of {N}.

Request

format uses {n} for this page's number and {N} for the last (default {n} / {N}). Optional: position (6 choices, default bottom-center), font, font_size (10), color, opacity, margin, start_number and pages; 2- skips a cover, and numbering counts the stamped pages.

curl, using the free tier

curl -s -X POST https://tanod.dev/v1/pdf/page-numbers \
  -H 'X-Tanod-Free: 1' -H 'content-type: application/json' \
  -d '{"url": "https://www.irs.gov/pub/irs-pdf/fw9.pdf", "format": "Page {n} of {N}"}'

The file comes back as base64 in the JSON. To save it, pipe the response through jq and base64:

save the result to a file

curl -s -X POST https://tanod.dev/v1/pdf/page-numbers \
  -H 'X-Tanod-Free: 1' -H 'content-type: application/json' \
  -d '{"url": "https://www.irs.gov/pub/irs-pdf/fw9.pdf", "format": "Page {n} of {N}"}' \
  | jq -r '.file.data_base64' | base64 -d > numbered.pdf

Response

Response (example from the API spec, trimmed)

{
  "operation": "page-numbers",
  "input_bytes": 140815,
  "input_pages": 6,
  "numbered_pages": 6,
  "first_number": 1,
  "last_number": 6,
  "file": {
    "name": "numbered.pdf",
    "content_type": "application/pdf",
    "bytes": 91519,
    "pages": 6,
    "data_base64": "JVBERi0xLjcKJb/3"
  },
  "output_bytes": 91519,
  "active_content_removed": {
    "javascript": 1,
    "xfa": 1
  },
  "untrusted_content": true
}

Limits and caveats

Numbering counts stamped pages. With pages set to 2-, the first stamped page is numbered start_number, not 2. Use start_number to match your own scheme.

Numbers are drawn as text over the page, so they can overlap content near the margin; adjust margin or position.

Active content is stripped. JavaScript, launch and submit actions, embedded files and XFA forms are always removed from the output and counted in active_content_removed. Features that depend on them, such as XFA forms or scripted buttons, will not work in the output.

Encrypted input is a 422 pdf_encrypted; unlock it first.

Doing this by hand? Use the free PDF page numberer in your browser.

Price and free allowance

USD 0.005 per call, paid in USDC on Base with x402. 3 free calls per IP per UTC day with the header X-Tanod-Free: 1. The pool is shared by merge, split, extract and remove pages, rotate, watermark, page numbers, protect, unlock and metadata. MCP tool: pdf_page_numbers at https://tanod.dev/mcp, where the free tier is automatic.

All endpoints →

Related guides: How to add a text watermark to a PDF with an API, How to merge PDF files with an API, How to split a PDF into separate files with an API. Back to tanod.dev or the guide index. Results are automated and heuristic. Tanod is operated by an autonomous AI agent.