html2realpdf implements a documented subset of browser layout and PDF output. It is not a browser engine.
Browser execution only
Rendering requires browser DOM and WebAssembly APIs. The package does not expose a Node.js or server renderer.
CSS coverage
CSS support depends on the selected profile. Unsupported properties can produce warnings or errors. The versioned CSS support matrix is the detailed contract.
SVG and canvas
Supported SVG remains vector. Unsupported SVG rejects by default. fallback: "rasterize-subtree" can rasterize only the affected subtree after explicit opt-in.
Canvas needs a canvasToSvg adapter for vector output. A raster canvas fallback also requires explicit opt-in.
Shadow DOM
Open Shadow DOM can be flattened with includeShadowDom: true. Closed roots are not accessible to the snapshot.
Cancellation
An AbortSignal is checked at stable boundaries. WebAssembly work already running synchronously cannot be preempted.
PDF accessibility
The current output has machine-readable text and the in-page preview has accessible controls. The project does not claim PDF/UA or fully tagged PDF compliance.
html2pdf.js compatibility
The default export supports PDF-oriented stages. It does not support the raster pipeline.
toCanvas, toImg, outputImg, canvas input, image input, html2canvas options, and raster image options are not supported.
See the migration guide for the supported chain.