DeckHTML accepts a local HTML file, HTML from stdin, one or more HTML files, or a URL. Multiple input files are converted in the order supplied. A single HTML document can also produce multiple slides when DeckHTML detects slide containers, or when you provide a slide selector through the programmatic API.
DeckHTML loads HTML in Chromium and inspects the rendered DOM rather than parsing source markup alone. This means computed layout, CSS, web fonts, and browser-rendered content inform the output. Give pages that load data or fonts asynchronously enough time to settle before conversion.
The local engine translates inspected content into PowerPoint objects where possible: text, shapes, tables, images, SVGs, canvas content, and math each have dedicated handling. Fidelity depends on the source HTML and on what PowerPoint can represent. Content that cannot be reconstructed exactly may be simplified or rasterized; review the generated deck, especially after using complex CSS or embedded content.
--mode auto uses cloud execution when an API key is available and local execution otherwise. --mode local always uses the local engine and requires no authentication. --mode cloud can start as a rate-limited guest and is intended for cloud-only enhancements such as font embedding; sign in when prompted or when you need authenticated access.
pptxis the default editable PowerPoint output.pngwrites rendered image frames.
Use --report to write a conversion report next to the output, and --json when scripts need a machine-readable result on stdout.
The output can only render fonts installed on the machine that opens the presentation unless they are embedded. Use cloud mode with --embed-fonts when matched font embedding is required. Font availability and license terms remain your responsibility.
DeckHTML can inspect supported CSS and Anime.js entrance animations and write compatible PowerPoint animations. Slide transitions can be selected, cycled, randomized, or disabled. These features translate supported effects; they are not a guarantee that every browser animation has an equivalent in PowerPoint.
The CLI is designed for generators, CI, and agent workflows. Feed generated HTML through stdin, use --json to parse results, and keep diagnostics on stderr separate from data on stdout.