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Input
HTML or text
Modes
2 explicit
Runtime
Browser

Inspect bounded HTML parser diagnostics

Report up to 100 parser diagnostics with source positions and a clear non-conformance disclaimer.

Local processingNo sign-upNo resource loading

Check parser diagnostics

Source stays in this tab. Parser input is capped at 500 KiB; sanitizing uses 256 KiB.

Parser diagnostic report

Every result is inert, copyable source or data, never live DOM.

What this tool does

Explicit-mode, bounded, local parsing

HTML parsers recover from many errors. A zero-diagnostic result only means this parser reported no tracked parse errors; it is not full conformance, accessibility, security, or rendering proof.

Diagnostics are deliberately narrow

HTML parsers recover from many errors. A zero-diagnostic result only means this parser reported no tracked parse errors; it is not full conformance, accessibility, security, or rendering proof.

The parser runs locally with a 500 KiB input cap, 100,000-node and 100-level tree limits, and a 1 MiB output cap. It never fetches URLs, loads resources, uploads source, or saves a preset.

Explicit document and fragment modes

Document mode applies the HTML document parser and may supply implied html, head, or body structure. Fragment mode parses only a pasted fragment. The selected mode is part of the result and is never inferred from the text.

Primary references

Questions and answers

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