Unsupported input
The tool may reject input that does not match the expected content, structure, or file type.
Fix: Confirm the tool input requirements and paste the correct type of data.
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View and preview HTML
Edit HTML and inspect the rendered result in a sandboxed preview pane.
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HTML (HyperText Markup Language) is the core markup language for web pages, defining structure and content that browsers render.
HTML Viewer is an online tool that helps you view HTML.
It opens HTML in a focused browser workspace so you can inspect structure, navigate large documents, and copy fragments cleanly.
Start with the HTML input you want to process in HTML Viewer.
Get a HTML result from HTML Viewer that is ready to review, copy, and reuse in the next step of your workflow.
The tool may reject input that does not match the expected content, structure, or file type.
Fix: Confirm the tool input requirements and paste the correct type of data.
Missing fields or partial content can block processing or produce weak results.
Fix: Provide the full required input before running the tool.
Sample or placeholder values can lead to output that looks valid but is not ready for real use.
Fix: Replace placeholders with your actual values before relying on the result.
Inputs are persisted to your browser's local storage between reloads — you can close the tab and come back to the same regex or input later. The data stays on your device.
Yes. All standard JavaScript regex flags — g, i, m, s, u, y — are exposed as checkboxes in the UI, and the flag string is included when you copy the pattern.
Matches can be exported as JSON (one object per match with index, value, and capture groups), CSV, or a raw list. The export respects the current flags and input.
Yes. Once the page has loaded, all processing is client-side — you can pull the Wi-Fi cable and HTML Viewer keeps working for the rest of the session.
HTML Viewer uses the JavaScript (ECMAScript) regex engine, which is ~99% compatible with PCRE for common features (character classes, quantifiers, groups, backreferences). Features unique to PCRE (e.g., recursive patterns, possessive quantifiers) aren't supported and the tool flags them on paste.
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