Convert a URL to PDF with curl

The convert endpoint is synchronous by default: the call holds until the render finishes, then answers 200 with a JSON receipt. The receipt is metadata, not the document; the bytes live behind the receipt's download url, and that url only answers to your key.

The recipe

ORIGIN="https://webcapture.io"

RECEIPT=$(curl -sS -X POST "$ORIGIN/v1/convert" \
  -H "Authorization: Bearer wc_your_key" \
  -H "Content-Type: application/json" \
  -d '{"url": "https://example.com/"}')
echo "$RECEIPT"
# {"id": "cnv_9f2c01ab", "bytes": 158120, "attempts": 1,
#  "remaining": 49, "sourceUrl": "https://example.com/", "sourceType": "url",
#  "download": ".../v1/conversions/cnv_9f2c01ab.pdf"}

ID=$(printf '%s' "$RECEIPT" | sed -E 's/.*"id": *"([^"]+)".*/\1/')
case "$ID" in cnv_*) ;; *) echo "convert failed: $RECEIPT" >&2; exit 1 ;; esac

# fetch the bytes with the same header:
curl -sS -H "Authorization: Bearer wc_your_key" \
  -o page.pdf \
  "$ORIGIN/v1/conversions/$ID.pdf"

The first call renders example.com and answers with the receipt: id, bytes, attempts, remaining (renders left this month), sourceUrl, sourceType, and download. The second call fetches that download url and writes page.pdf. One render, one document against the key's quota, and the receipt's remaining field tells you where the month stands.

Same-key GET: 401 without it; 404 for another key.

The fields this recipe uses

• url: the page address to render, a public http(s) URL.
• format: pdf is the default; png, jpeg, webp, and markdown exist too.

Related

• Next: Get a free key to run this curl recipe, or read the API docs.
• More recipes: Python: convert from a URL, Node: convert from a URL, curl: print page ranges.
• The webcapture API reference: every field the convert endpoint admits, with the response shapes and the error table.
• The recipes hub: the same endpoint in the other languages.
• Going deeper: if the printed page looks nothing like the browser showed it, the formatting guide names the three ways conversion loses layout.
• The free URL to PDF tool: try the render in a browser before you wire the call.

Method

Source: convert field reference, checked 2026-10-05. Corrections.