carta

A universal document converter written in Rust. Read a markup format, render it back out in another. A performant and lightweight reimplementation of pandoc.

Warning

carta is an early-stage alpha under active development. Not all of pandoc's formats are implemented yet and the API is still unstable.

Goals

• Performance and a smaller binary than pandoc.
• Feature parity with pandoc across all formats and extensions.
• A developer-friendly library, with the CLI as a thin shell over it.

Status

This tracks carta's status of all formats pandoc supports. See STATUS.md for a detailed per-format breakdown including extension coverage, and the full feature backlog.

✅ usable — basically done; any remaining parity gaps are minor and unlikely to affect regular use · 🚧 in development — large parity gaps or breaking issues (e.g. panics), not recommended for use yet · ❌ not started · ➖ not applicable (pandoc has no such direction)

Markdown family

Format	Reader	Writer
CommonMark (commonmark)	✅	✅
CommonMark-X (commonmark_x)	✅	✅
GitHub-Flavored Markdown (gfm)	✅	✅
Pandoc Markdown (markdown)	✅	✅
Markdown strict (markdown_strict)	✅	✅
MultiMarkdown (markdown_mmd)	✅	✅
PHP Markdown Extra (markdown_phpextra)	✅	✅
GitHub Markdown, legacy (markdown_github)	✅	✅
Djot (djot)	❌	❌
Markua (markua)	➖	❌

HTML & slides

Format	Reader	Writer
HTML (html, html5, html4)	✅	✅
Chunked HTML (chunkedhtml)	➖	❌
reveal.js (revealjs)	➖	✅
Beamer (beamer)	➖	✅
Slidy (slidy)	➖	❌
S5 (s5)	➖	❌
Slideous (slideous)	➖	❌
DZSlides (dzslides)	➖	❌
PowerPoint (pptx)	❌	❌

TeX & typesetting

Format	Reader	Writer
LaTeX (latex)	✅	✅
Typst (typst)	❌	✅
ConTeXt (context)	➖	❌
Texinfo (texinfo)	➖	❌
PDF (pdf)	➖	❌

Lightweight markup

Format	Reader	Writer
reStructuredText (rst)	✅	✅
AsciiDoc (asciidoc)	❌	✅
AsciiDoc legacy (asciidoc_legacy)	➖	❌
Asciidoctor (asciidoctor)	➖	❌
Org mode (org)	✅	✅
Textile (textile)	❌	❌
Muse (muse)	❌	❌
Haddock (haddock)	❌	❌
txt2tags (t2t)	❌	➖
Perl POD (pod)	❌	➖

Wikis

Format	Reader	Writer
MediaWiki (mediawiki)	✅	✅
DokuWiki (dokuwiki)	✅	✅
Jira (jira)	✅	✅
Creole (creole)	❌	➖
TikiWiki (tikiwiki)	❌	➖
TWiki (twiki)	❌	➖
Vimwiki (vimwiki)	❌	➖
XWiki (xwiki)	➖	❌
ZimWiki (zimwiki)	➖	❌

roff

Format	Reader	Writer
man (man)	✅	✅
mdoc (mdoc)	❌	➖
ms (ms)	➖	❌
vimdoc (vimdoc)	➖	❌

Word processor, ebook & notebook

Format	Reader	Writer
Word (docx)	❌	❌
OpenDocument Text (odt)	❌	❌
OpenDocument (opendocument)	➖	❌
EPUB (epub, epub2, epub3)	❌	✅
Jupyter Notebook (ipynb)	✅	✅
FictionBook2 (fb2)	❌	❌
InDesign ICML (icml)	➖	❌
Rich Text Format (rtf)	❌	❌
Spreadsheet (xlsx)	❌	➖

XML & publishing

Format	Reader	Writer
DocBook (docbook, docbook4, docbook5)	❌	❌
JATS (jats, jats_archiving, jats_articleauthoring, jats_publishing)	❌	❌
BITS (bits)	❌	➖
TEI (tei)	➖	❌
Generic XML (xml)	❌	❌

Bibliography

Format	Reader	Writer
BibTeX (bibtex)	❌	❌
BibLaTeX (biblatex)	❌	❌
CSL JSON (csljson)	❌	❌
RIS (ris)	❌	➖
EndNote XML (endnotexml)	❌	➖

Data, interchange & terminal

Format	Reader	Writer
Pandoc JSON (json)	✅	✅
Native Pandoc AST (native)	✅	✅
OPML (opml)	✅	✅
CSV (csv)	✅	➖
TSV (tsv)	✅	➖
Plain text (plain)	➖	✅
BBCode (bbcode, bbcode_phpbb, bbcode_steam, …)	➖	❌
ANSI terminal (ansi)	➖	❌

Installation

Prebuilt binaries

Download the archive for your platform from the latest release. Builds are provided for Linux (x86-64 gnu and static musl, arm64), macOS (Intel and Apple Silicon), and Windows (x86-64).

From crates.io

cargo install carta

This installs the carta binary. For a smaller build, pass --no-default-features with only the formats you need, e.g. --features cli,read-commonmark,write-html.

From source

git clone https://github.com/mfkrause/carta
cd carta
cargo build --release
# binary at target/release/carta

Usage

Command line

# CommonMark to HTML
carta -f commonmark -t html input.md -o output.html

# read from stdin, write to stdout
echo '# Hello' | carta -f commonmark -t html

# inspect the document model
carta -f commonmark -t json input.md

# standalone document with a table of contents and numbered sections
carta -f commonmark -t html -s --toc --number-sections input.md -o output.html

# render HTML math with MathJax (or --katex)
carta -f commonmark -t html -s --mathjax input.md -o output.html

# extract a notebook's embedded images to files, rewriting the references
carta -f ipynb -t markdown --extract-media=media notebook.ipynb -o notebook.md

# transform the document through a JSON filter before writing (repeatable, applied in order)
carta -f commonmark -t html -F ./my-filter.py input.md -o output.html

# discover what this build supports
carta --list-input-formats
carta --list-output-formats
carta --list-extensions          # extensions for the Markdown dialect
carta --list-extensions=gfm      # extensions and defaults for a given format

Library

use carta::{convert_text, ReaderOptions, WriterOptions};

let html = convert_text(
    "commonmark",
    "html",
    "# Hello, *world*",
    &ReaderOptions::default(),
    &WriterOptions::default(),
)?;

convert_text is the shortcut for text-to-text conversion. The general entry point is convert, which takes raw bytes and returns an Output that is text or bytes depending on the target format — use it when either side is a binary format.

You can select formats at compile time via per-direction features to make binaries even more lightweight for your individual needs.

cargo build -p carta --no-default-features --features read-commonmark,write-html

Development

cargo build                         # build the workspace
cargo nextest run --workspace       # run tests
cargo clippy --all-targets          # lint
cargo +nightly fuzz run commonmark  # fuzz a reader (see fuzz/README.md)

The workspace splits into carta-ast (the document model), carta-core (shared traits and options), carta-readers, carta-writers, and carta (the library facade, which also ships the command-line binary behind its cli feature).

License

Copyright © 2026 Maximilian Krause.

carta is free software: you can redistribute it and/or modify it under the terms of the GNU Affero General Public License, version 3, as published by the Free Software Foundation. See LICENSE for the full text.