html-to-markdown

<!-- AI-RULEZ :: GENERATED FILE — DO NOT EDIT Content-Hash: blake3:c60ca71925e3dec29b8b9dfc1e2775c899c932e93fca99e659fb0aac87ac79e4 Source-Hash: blake3:b863a9279a8e31251a475dd8c895529ec38eec6b6506af4fe5c874832e9a48a6 Schema-Version: v1 --> # html-to-markdown html-to-markdown is a high-performance HTML→Markdown converter with a Rust core and 12 native language bindings. It converts HTML to CommonMark Markdown, Djot, or plain text in a single pass, optionally extracting metadata, tables, inline images, and a structured document tree. Use this skill when writing code that: - Converts HTML strings, files, or live URLs to Markdown, Djot, or plain text - Extracts metadata (title, OG tags, JSON-LD/Microdata/RDFa, headers, links, images, language) from HTML - Extracts structured table data (GFM markdown + cell grids) from HTML - Extracts a structured document-structure tree - Extracts inline images (data URIs, SVGs) from HTML - Uses preprocessing to clean noisy HTML (ads, navigation, forms) before conversion ## Capability map | Capability | CLI | SDKs | | ---------- | --- | ---- | | HTML→Markdown / Djot / plain text | `html-to-markdown FILE` | `convert(html, options)` | | Read HTML from stdin / file / URL | `cat f \| …`, `FILE`, `--url URL` | `convert(htmlString, …)` | | ~30 config options (headings, code blocks, lists, escaping, wrapping…) | flags | `ConversionOptions` | | Metadata extraction | `--json` (default-extracted) | `result.metadata` | | Table extraction | `--json` → `tables[]` | `result.tables` | | Document structure tree | `--json --include-structure` | `include_document_structure=true` | | Inline image extraction | `--json --extract-inline-images` | `extract_images=true` | | HTML preprocessing | `--preprocess [--preset …]` | `PreprocessingOptions` | | Extraction-only (no Markdown body) | `--json --no-content` | options + read fields | ## Installation ### CLI ```bash # (Homebrew 6.0+ requires explicit trust for third-party taps) brew trust xberg-io/tap brew install xberg-io/tap/html-to-markdown # or run without a persistent install (the CLI proxy package self-installs the binary): npx @xberg-io/html-to-markdown-cli --help uvx --from html-to-markdown-cli html-to-markdown --help # or download a prebuilt binary from the latest GitHub release: # https://github.com/xberg-io/html-to-markdown/releases/latest # or build from source: cargo install html-to-markdown-cli ``` ### Language SDKs ```bash pip install html-to-markdown # Python npm install @xberg-io/html-to-markdown # TypeScript / Node.js cargo add html-to-markdown-rs # Rust (features: metadata default; full = all) gem install html-to-markdown # Ruby composer require xberg-io/html-to-markdown # PHP go get github.com/xberg-io/html-to-markdown/packages/go/v3 # Go dotnet add package XbergIo.HtmlToMarkdown # C# npm install @xberg-io/html-to-markdown-wasm # WASM ``` - Java (Maven): `io.xberg:html-to-markdown` - Elixir: `{:html_to_markdown, "~> 3.8"}` in `mix.exs` - R: `install.packages("htmltomarkdown", repos = "https://xberg-io.r-universe.dev")` - C (FFI): pre-built `.so` / `.dll` / `.dylib` from GitHub releases ## CLI vs SDK — which to use - **CLI** — one-shot conversions, shell pipelines, fetching a single URL, ad-hoc metadata/table extraction via `--json | jq`. Flags only for conversion (`FILE` is positional; omit or use `-` for stdin); the only subcommand is `mcp`. - **SDK** — embedding conversion in application code, batch processing, custom element conversion (visitor pattern, Rust), and tight loops where process spawn overhead matters. - **MCP server** — `html-to-markdown mcp` exposes `convert_html` and `extract_metadata` as agent tools, so an MCP client can convert an HTML string directly with no shell-out. This plugin auto-registers it; see the **using-the-mcp-server** skill. Both share the same `ConversionResult` shape, so output is interchangeable. ## When to use html-to-markdown vs xberg vs crawlberg - **html-to-markdown** — you already have HTML (a string, a file, or a single URL) and want clean Markdown plus structured metadata/tables. No OCR, no document parsing, no crawling. - **xberg** — you have *documents* (PDF, Office, images, email, archives) and need full text/table/metadata extraction with optional OCR. Use it when the input is not already HTML. - **crawlberg** — you need to *crawl or scrape many pages*, follow links, and handle JS-rendered sites with a headless-Chrome fallback. It uses html-to-markdown internally for the HTML→Markdown step. Rule of thumb: single HTML in → Markdown out = html-to-markdown. Many URLs / a site = crawlberg. Non-HTML documents = xberg. ## CLI quick start ```bash # Convert a file to stdout html-to-markdown input.html # Convert and save html-to-markdown input.html -o output.md # Read from stdin cat page.html | html-to-markdown # Fetch and convert a URL html-to-markdown --url https://example.com > out.md # Full ConversionResult as JSON (content, tables, metadata, images, warnings) html-to-markdown --json input.html # JSON with document structure tree html-to-markdown --json --include-structure input.html # Extraction-only (no Markdown body) html-to-markdown --json --no-content input.html # Aggressive web-page cleanup html-to-markdown input.html --preprocess --preset aggressive ``` ## SDK quick start ### Rust ```rust use html_to_markdown_rs::convert; let result = convert("<h1>Hello World</h1><p>A paragraph.</p>", None)?; println!("{}", result.content.unwrap_or_default()); ``` ### Python ```python from html_to_markdown import convert result = convert("<h1>Hello World</h1><p>A paragraph.</p>") print(result.content) # # Hello World\n\nA paragraph. print(result.metadata) # title, links, headers, … ``` ### TypeScript / Node.js ```typescript import { convert } from "@xberg-io/html-to-markdown"; // Node's convert() returns a ConversionResult object directly. const result = convert("<h1>Hello World</h1><p>A paragraph.</p>"); console.log(result.content); ``` ## ConversionResult fields All languages return the same structure (dict, object, or struct). | Field | Description | | ----- | ----------- | | `content` | Converted text (Markdown/Djot/plain). `null` only in extraction-only mode. | | `metadata` | Title, OG, headers, links, images, structured data. | | `tables` | Tables with `grid` (structured cells) and `markdown` fields. | | `images` | Extracted inline images (requires inline-image extraction). | | `document` | Structured document tree when structure extraction is enabled. | | `warnings` | Non-fatal processing warnings (`message`, `kind`). | ## Configuration All languages expose the same ~30 options. See [references/configuration.md](references/configuration.md) for the complete table. Common ones: | Option | Values | Default | | ------ | ------ | ------- | | `heading_style` | `atx`, `underlined`, `atx-closed` | `atx` | | `code_block_style` | `backticks`, `indented`, `tildes` | `backticks` | | `output_format` | `markdown`, `djot`, `plain` | `markdown` | | `wrap` / `wrap_width` | bool / 20–500 | off / `80` | | `autolinks` (SDK) / `--no-autolinks` (CLI) | bool / flag | `true` (on); disable in CLI with `--no-autolinks` | | preprocessing | `minimal` / `standard` / `aggressive` | off | ### Rust (builder) ```rust use html_to_markdown_rs::{convert, ConversionOptions, HeadingStyle, OutputFormat}; let options = ConversionOptions::builder() .heading_style(HeadingStyle::Atx) .output_format(OutputFormat::Markdown) .wrap(true) .wrap_width(100) .build(); let result = convert(html, Some(options))?; ``` ### Python (dataclass) ```python from html_to_markdown import convert, ConversionOptions, PreprocessingOptions result = convert( html, ConversionOptions(heading_style="atx", wrap=True, wrap_width=100), PreprocessingOptions(enabled=True, preset="aggressive"), ) ``` ## Metadata extraction Metadata is extracted by default; in the CLI it appears under `metadata` in `--json` output. Fields include `document` (title, description, language, charset, open_graph), `headers`, `links` (with `link_type`), `images`, and `structured_data` (JSON-LD/Microdata/RDFa). See the **extracting-metadata** skill for details. ## Table extraction Tables appear in `result.tables`, each with a pre-rendered `markdown` string and a structured cell `grid`. Markdown tables also appear inline in `content`. See the **extracting-tables** skill. ## Document structure extraction Enable structure extraction (`--include-structure` on the CLI, `include_document_structure=true` in SDKs) to get a semantic node tree under `document`. Node types include `heading`, `paragraph`, `list`, `list_item`, `table`, `image`, `code`, `quote`, `group`, `metadata_block`. ## Common pitfalls 1. **`convert()` returns a result object, not a string.** Access `.content` for the Markdown text. This holds for Node.js too — `convert()` returns a `ConversionResult` object directly; do **not** `JSON.parse()` it. 2. **`--json` outputs JSON, not Markdown.** Omit `--json` for plain Markdown. 3. **`--include-structure`, `--extract-inline-images`, and `--no-content` require `--json`.** 4. **The conversion CLI is flags-only.** `FILE` is positional; the only subcommand is `mcp` (starts the MCP server). 5. **`--preset`, `--keep-navigation`, `--keep-forms` require `--preprocess`.** ## Additional resources - **[CLI Reference](references/cli-reference.md)** — every flag, JSON shape, exit codes - **[Configuration Reference](references/configuration.md)** — all 30+ options with defaults - **[Rust API Reference](references/rust-api.md)** — signatures, builder, feature flags - **[Python API Reference](references/python-api.md)** — functions, dataclasses, type hints - **[TypeScript API Reference](references/typescript-api.md)** — functions, interfaces, Buffer support - **[Other Bindings](references/other-bindings.md)** — Go, Ruby, PHP, Java, C#, Elixir, R, WASM, C FFI GitHub: <https://github.com/xberg-io/html-to-markdown>