Htmlcsstoimage

The API has a single primary endpoint: POST /v1/image with a JSON body containing html (required), css (optional), url (alternative to html), width, height, and output format parameters. The response returns a url to the hosted image (or the image bytes if requested). GET /v1/image/{id} retrieves a previously created image. The surface is minimal and well-defined. No SDK required — direct HTTP POST. Rate limits are plan-based. The API versioning is stable (v1).

The API returns standard HTTP status codes: 200 for successful creation, 400 for invalid HTML or parameters, 401 for auth failures, 429 for rate limit exceeded. Error bodies include a message field describing the issue. Rendering failures (JavaScript errors in the HTML, font loading failures) may still return 200 with a partially rendered image — no explicit rendering-error signal documented. No webhook for async completion; the API is synchronous. Timeout behavior for complex pages is not documented.

HTML/CSS to Image is a REST API that converts HTML/CSS templates or URLs into PNG, JPEG, or PDF outputs. The API is highly agent-native: an agent POSTs an HTML string (with optional CSS and viewport config) and receives back a URL to the rendered image within seconds. This is directly useful for agents generating social cards, report screenshots, dynamic images from templates, or archiving web content as images. The API supports Google Fonts, custom fonts, and JavaScript rendering. Pricing is per image with free trial credits. Confidence is docs-derived; rendering latency for complex pages is not runtime-verified.

Authentication uses HTTP Basic Auth with user_id as username and api_key as password. Keys are generated in the HCTI dashboard. No OAuth or per-request signing. Key rotation is manual. No IP allowlisting documented. Standard basic auth model — straightforward for agent use. The user_id + api_key pair must be base64-encoded for the Authorization header as per HTTP Basic Auth spec.

Documentation at htmlcsstoimage.com/docs covers the API reference, authentication, supported parameters, and examples for common use cases (social cards, PDFs, templates). Code examples in multiple languages (curl, Node, Python, Ruby, PHP). The API reference is complete and concise. Integration guides for popular frameworks are provided. Community support via email and chat. Documentation quality is good for the core use case; edge cases (font loading, JavaScript timeouts) are less documented.