A pure Python HTML5 parser that just works. No C extensions to compile. No system dependencies to install. No complex API to learn.
📖 Read the full documentation here
- Just... Correct ✅ — Spec-perfect HTML5 parsing with browser-grade error recovery — passes the official 9k+ html5lib-tests suite, with 100% line+branch coverage. (Correctness)
- Just... Python 🐍 — Pure Python, zero dependencies — no C extensions or system libraries, easy to debug, and works anywhere Python runs (including PyPy and Pyodide). (Quickstart)
- Just... Secure 🔒 — Safe-by-default output for untrusted HTML — built-in Bleach-style allowlist sanitization on
to_html()/to_markdown()(override withsafe=False), plus URL/CSS rules. (Sanitization & Security) - Just... Query 🔍 — CSS selectors out of the box — one method (
query()), familiar syntax (combinators, groups, pseudo-classes), and plain Python nodes as results. (CSS Selectors) - Just... Fast Enough ⚡ — Fast for the common case (fastest pure-Python HTML5 parser available); for terabytes, use a C/Rust parser like
html5ever. (Benchmarks)
| Parser | HTML5 Compliance | Pure Python? | Speed | Query API | Notes |
|---|---|---|---|---|---|
| JustHTML | ✅ 100% | ✅ Yes | ⚡ Fast | ✅ CSS selectors | It just works. Correct, easy to install, and fast enough. |
html5lib |
🟡 88% | ✅ Yes | 🐢 Slow | ❌ None | The reference implementation. Very correct but quite slow. |
html5_parser |
🟡 84% | ❌ No | 🚀 Very Fast | 🟡 XPath (lxml) | C-based (Gumbo). Fast and mostly correct. |
selectolax |
🟡 68% | ❌ No | 🚀 Very Fast | ✅ CSS selectors | C-based (Lexbor). Very fast but less compliant. |
BeautifulSoup |
🔴 4% | ✅ Yes | 🐢 Slow | 🟡 Custom API | Wrapper around html.parser. Not spec compliant. |
html.parser |
🔴 4% | ✅ Yes | ⚡ Fast | ❌ None | Standard library. Chokes on malformed HTML. |
lxml |
🔴 1% | ❌ No | 🚀 Very Fast | 🟡 XPath | C-based (libxml2). Fast but not HTML5 compliant. |
Compliance scores from a strict run of the html5lib-tests tree-construction fixtures (1,743 non-script tests). See benchmarks/correctness.py and docs/correctness.md for details.
Requires Python 3.10 or later.
pip install justhtmlfrom justhtml import JustHTML
doc = JustHTML("<html><body><p class='intro'>Hello!</p></body></html>")
# Query with CSS selectors
for p in doc.query("p.intro"):
print(p.name) # "p"
print(p.attrs) # {"class": "intro"}
print(p.to_html()) # <p class="intro">Hello!</p>See the Quickstart Guide for more examples including tree traversal, streaming, and strict mode.
If you installed JustHTML (for example with pip install justhtml or pip install -e .), you can use the justhtml command.
If you don't have it available, use the equivalent python -m justhtml ... form instead.
# Pretty-print an HTML file
justhtml index.html
# Parse from stdin
curl -s https://example.com | justhtml -
# Select nodes and output text
justhtml index.html --selector "main p" --format text
# Select nodes and output Markdown (subset of GFM)
justhtml index.html --selector "article" --format markdown
# Select nodes and output HTML
justhtml index.html --selector "a" --format html# Example: extract Markdown from GitHub README HTML
curl -s https://github.com/EmilStenstrom/justhtml/ | justhtml - --selector '.markdown-body' --format markdown | head -n 15Output:
# JustHTML
[](#justhtml)
A pure Python HTML5 parser that just works. No C extensions to compile. No system dependencies to install. No complex API to learn.
**[📖 Read the full documentation here](/EmilStenstrom/justhtml/blob/main/docs/index.md)**
## Why use JustHTML?
- **Just... Correct ✅** — Spec-perfect HTML5 parsing with browser-grade error recovery — passes the official 9k+ [html5lib-tests](https://github.com/html5lib/html5lib-tests) suite, with 100% line+branch coverage. ([Correctness](/EmilStenstrom/justhtml/blob/main/docs/correctness.md))
- **Just... Python 🐍** — Pure Python, zero dependencies — no C extensions or system libraries, easy to debug, and works anywhere Python runs (including PyPy and Pyodide). ([Quickstart](/EmilStenstrom/justhtml/blob/main/docs/quickstart.md))
- **Just... Secure 🔒** — Safe-by-default output for untrusted HTML — built-in Bleach-style allowlist sanitization on `to_html()` / `to_markdown()` (override with `safe=False`), plus URL/CSS rules. ([Sanitization & Security](/EmilStenstrom/justhtml/blob/main/docs/sanitization.md))
See CONTRIBUTING.md for development setup and guidelines.
JustHTML started as a Python port of html5ever, the HTML5 parser from Mozilla's Servo browser engine. While the codebase has since evolved significantly, html5ever's clean architecture and spec-compliant approach were invaluable as a starting point. Thank you to the Servo team for their excellent work.
Correctness and conformance work is heavily guided by the html5lib ecosystem and especially the official html5lib-tests fixtures used across implementations.
The sanitization API and threat-model expectations are informed by established Python sanitizers like Bleach and nh3.
The CSS selector query API is inspired by the ergonomics of lxml.cssselect.
MIT. Free to use both for commercial and non-commercial use.