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.
HTML Viewer
View and preview HTML
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What is HTML Viewer
Written by Giorgos Kostas. Last reviewed:
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.
Why use it
- Work through HTML faster with a focused browser-based workflow.
- Review HTML input and output without switching between extra tools.
- Catch HTML issues earlier while the data or content is still in front of you.
- Keep HTML results easy to copy back into your project or process.
Example (before/after)
HTML input
Start with the HTML input you want to process in HTML Viewer.
HTML output
Get a HTML result from HTML Viewer that is ready to review, copy, and reuse in the next step of your workflow.
Common errors
Incomplete values
Missing fields or partial content can block processing or produce weak results.
Fix: Provide the full required input before running the tool.
Copying placeholder content
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.
FAQ
Can I save sessions in HTML Viewer?
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.
Does HTML Viewer support multi-line mode and flags?
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.
Can I export matches from HTML Viewer?
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.
Does HTML Viewer work without an internet connection?
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.
What regex flavor does HTML Viewer use?
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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