JustHTML
A pure Python HTML5 parser that just works
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I got frustrated with HTML parsing in Python.I wanted a Python HTML parser that was both correct and easy to install. The C-based ones (lxml, selectolax) are fast but not HTML5 compliant. The pure Python ones (html.parser, BeautifulSoup's default) are easy to install but choke on real-world HTML. html5lib is 80% correct but painfully slow.So I wrote JustHTML. It's:• 100% HTML5 compliant – passes all 8,500+ html5lib tests. If a browser can parse it, JustHTML can.• Pure Python, zero dependencies – pip install and go. Works on PyPy, Pyodide, anywhere.• Fast enough – ~0.1s to parse Wikipedia's homepage. Not C-fast, but 50% faster than html5lib.• Simple API – doc.query("div.foo > p") with CSS selectors. One method to learn.Example: from justhtml import JustHTML doc = JustHTML("<div><p class='intro'>Hello!</p></div>") print(doc.query(".intro")[0].to_html()) I've fuzz-tested it with 3 million malformed documents.Would love feedback, especially on the API design.
HN · launched Dec 2, 2025 · 6 upvotes (top 73%) · 0 views
Niche: data parsing libraries and tools · 71 launches, 1 in the last 7 days · Explore this niche →
Category and tags
- Horizontal
- Dev tools
- Developer
- Not AI
- Hobby / open-source project
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More like this: all 71 launches in data parsing libraries and tools →
Could you build this?
Partial Implementing a full HTML5-compliant specification parser in pure Python involves an enormous, notoriously complex state machine with exhaustive edge-case error recovery rules.
What it would actually take: The WHATWG HTML specification requires implementing hundreds of specific tokenization and tree-construction states, insertion modes, and adoption agency algorithms. Building a compliant parser requires writing and debugging against the extensive html5lib-tests suite, tracking complex token-stream mutations, and handling subtle character encoding fallbacks. A developer would need deep knowledge of the WHATWG parsing algorithm and months of rigorous testing against edge cases.
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Competitors
Other products that read as similar to this one : 180 launches clear the similarity bar, closest 8 shown.
Attention rank: #154 of 181 (itself plus its competitors, highest first, normalized so YC and Product Hunt are compared fairly).
Launched 31 days after the earliest competitor.
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