POST /convert/html

POSThttps://api.rendarium.com/convert/html

Converts an HTML string to PDF. Costs 1 credit per successful request on the hosted API; nothing in self-hosted mode. The example on the home page and the quick start call exactly this operation.

Request

POST /convert/html
Authorization: Bearer rnd_live_...
Content-Type: application/json

{ "html": "<h1>Hello</h1>", "options": { "page_size": "A4" } }

Field	Type	Description
`html`	string, required	The HTML document to render. Maximum 2 MB. Inline CSS and `<style>` are supported; external resources are fetched relative to `options.base_url`.
`options`	object, optional	Rendering options, all optional — see below.

Options

Option	Type	Description
`page_size`	string	`A4` (default), `Letter`, `Legal`, `A3`, `A5` or `WIDTHxHEIGHTmm`
`orientation`	string	`portrait` (default) or `landscape`
`margins_mm`	number \| object	Uniform margin, or `{top, right, bottom, left}`; default 20
`base_url`	string	Base URL used to resolve relative images, stylesheets and fonts in the HTML
`header_html / footer_html`	string	HTML rendered on every page; placeholders `{page}` and `{pages}`
`wait_ms`	integer	Extra delay after load before capture, 0–30000; for JavaScript-driven content
`wait_for_selector`	string	Capture once this CSS selector exists in the page
`pdf_ua`	boolean	Produce a tagged PDF/UA document from the HTML structure
`pdf_a`	string	`2b`, `2u`, `3b` — archival PDF/A conformance level
`password`	object	`{user, owner, permissions}` — encrypt the output

Response

200 OK with Content-Type: application/pdf; the body is the PDF. Headers: Request-Id, Rendarium-Version, Content-Length.

HTTP/1.1 200 OK
Content-Type: application/pdf
Content-Length: 18432
Request-Id: 7f1c9b2e-3a4d-4e5f-9a6b-1c2d3e4f5a6b

Errors

Every error is JSON {"error": "<code>", "detail": "..."}. Codes are stable identifiers to branch on; detail is for humans and may change.

Error	HTTP	Meaning
`invalid_api_key`	401	Header missing, key unknown, key revoked, or the account's email is not confirmed. The same code for every cause, deliberately.
`account_suspended`	403	The account is suspended. Portal login still works; contact support.
`invalid_request`	400	`html` missing, not a string, or larger than 2 MB; malformed JSON. `detail` says which.
`quota_exceeded`	429	No credits left. Buy a top-up or upgrade at app.rendarium.com/billing; the allowance also resets on your billing day. Not charged.
`rate_limited`	429	More than 10 requests per second on this key. Back off and retry; not charged.
`conversion_failed`	500	The engine could not render the document. The reserved credit is refunded and the request appears as failed in your dashboard. Retry, or contact support with the request id.

All operations and credit costs: see the API index page (every operation listed, 1 credit each; measure, health and version are free).

Example: invoice with header and footer

curl -X POST https://api.rendarium.com/convert/html \
  -H "Authorization: Bearer rnd_live_YOUR_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "html": "<h1>Invoice #1024</h1><table>...</table>",
    "options": {
      "page_size": "A4",
      "margins_mm": { "top": 25, "right": 15, "bottom": 20, "left": 15 },
      "header_html": "<div style=\"font-size:10px\">Acme Ltd</div>",
      "footer_html": "<div style=\"font-size:10px;text-align:right\">Page {page} of {pages}</div>"
    }
  }' --output invoice.pdf