Sejda
Sejda HTML to PDF API

The only documented Sejda hosted REST API. Converts a URL or raw HTML to a PDF document via POST https://api.sejda.com/v2/html-pdf with a JSON body, authenticated with a Token (or publishable) API key. Sejda explicitly states it does not offer hosted API access to its other PDF tools (e.g. merge, compress).
Documentation GitHub OpenAPI
OpenAPI Specification

openapi: 3.0.1
info:
  title: Sejda HTML to PDF API
  description: >-
    The Sejda HTML to PDF API converts a web page URL or a raw HTML string into a
    PDF document. It is the only documented hosted REST API offered by Sejda; Sejda
    states it does not provide hosted API access to its other PDF tools (merge,
    compress, etc.). Requests are authenticated with a secret Token API key, or a
    publishable key for browser-side use with a configured allowed-domains list.
  termsOfService: https://www.sejda.com/terms-of-service
  contact:
    name: Sejda Support
    url: https://www.sejda.com/help
  version: '2'
servers:
  - url: https://api.sejda.com/v2
    description: Sejda API v2
paths:
  /html-pdf:
    post:
      operationId: htmlToPdf
      tags:
        - HTML to PDF
      summary: Convert a URL or HTML to a PDF document.
      description: >-
        Renders the supplied URL or raw HTML and returns the generated PDF as a
        binary stream. Provide either `url` or `htmlCode`. Some parameters are
        Pro-only and return HTTP 450 on free accounts. The generated PDF must be
        smaller than 50MB.
      security:
        - TokenAuth: []
      requestBody:
        required: true
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/HtmlToPdfRequest'
            examples:
              fromUrl:
                summary: Convert a URL
                value:
                  url: https://example.com
                  pageSize: a4
                  pageOrientation: auto
              fromHtml:
                summary: Convert raw HTML
                value:
                  htmlCode: '<html><body><h1>Hello</h1></body></html>'
                  pageSize: a4
      responses:
        '200':
          description: OK - the generated PDF document stream.
          content:
            application/pdf:
              schema:
                type: string
                format: binary
        '400':
          description: Invalid request.
        '403':
          description: Authorization failure or CORS / allowed-domain restriction.
        '413':
          description: Payload exceeds the 50MB limit.
        '429':
          description: Rate limit exceeded (requests-per-hour or concurrency).
        '450':
          description: A Pro-only parameter was used on a free account.
        '500':
          description: Server error - retry recommended.
        '550':
          description: Conversion failed (page unreachable or could not be loaded).
components:
  securitySchemes:
    TokenAuth:
      type: apiKey
      in: header
      name: Authorization
      description: >-
        Secret API key sent as `Authorization: Token: api_YOURAPIKEYHERE`. A
        publishable key (`api_public_...`) may be used for browser-side requests
        when the calling domain is on the account's allowed-domains list.
  schemas:
    HtmlToPdfRequest:
      type: object
      description: >-
        HTML-to-PDF conversion request. Supply either `url` or `htmlCode`.
        Pro-only fields are noted in their descriptions.
      properties:
        url:
          type: string
          format: uri
          description: URL of the web page to render to PDF.
        htmlCode:
          type: string
          description: Raw HTML to render to PDF (alternative to `url`).
        viewportWidth:
          type: integer
          description: Browser viewport width in pixels used while rendering.
        pageSize:
          type: string
          description: Output page size (e.g. a4, letter).
        pageOrientation:
          type: string
          description: Page orientation - auto, portrait, or landscape.
        pageMargin:
          type: number
          description: Page margin value.
        pageMarginUnits:
          type: string
          description: Units for the page margin (e.g. px, mm, in).
        hideNotices:
          type: boolean
          description: Hide notice elements when rendering.
        usePrintMedia:
          type: boolean
          description: Render using print media CSS rules.
        delay:
          type: integer
          description: Delay in milliseconds before capturing the page.
        scrollPage:
          type: boolean
          description: Scroll the page to trigger lazy-loaded content before rendering.
        authUsername:
          type: string
          description: HTTP basic auth username for protected source pages (Pro).
        authPassword:
          type: string
          description: HTTP basic auth password for protected source pages (Pro).
        waitForSelector:
          type: string
          description: Wait until a CSS selector is present before rendering (Pro).
        timezone:
          type: string
          description: Timezone used while rendering (e.g. America/New_York).
        lang:
          type: string
          description: Language hint for rendering (e.g. en).
Sejda HTML to PDF API

Documentation

Specifications

Other Resources

OpenAPI Specification
