The HTML Viewer That Lets You View, Highlight & Learn
Our tool is more than a simple viewer: it combines a powerful live preview with syntax highlighting and an explanation system. Use it to view any HTML, CSS, and JavaScript side by side, see which code drives which part of the page, and read clear explanations so you can learn as you view. Whether you are debugging a layout or learning web development, it is built for both viewing and learning.
No account required
Runs locally in browser
Import, edit, export workflow
A practical tool for checking and cleaning markup
Most quick editors either render output or edit code well, but not both in a clean workflow. This page focuses on daily tasks: verify output, inspect structure, clean formatting, and share results quickly.
Keep code and rendering side by side
Open the editor and preview together, then move between source and output without switching tabs. This is useful for debugging snippets, reviewing generated markup, and checking layout behavior before sharing.
Formatting and inspection are built into the same flow. You can paste messy markup, normalize indentation, verify output in preview, and export a clean file for handoff or commit.
Try the playgroundLive preview
See output update as you edit HTML, CSS, and JavaScript.
Code-to-output tracing
Use highlighting to connect source lines with rendered elements.
Clean export
Format markup and export a readable .html file for review or delivery.
Core features
Two-way highlight sync: click the code to see the matching preview element, or click an element in the preview to jump to the corresponding source line.
Two-way highlight sync (code ↔ preview)
The key idea is the mapping between source and rendered output. Click a line in the code: the matching element in the preview will highlight. Click an element in the preview: the code editor will jump to the corresponding line and highlight it too. Note: when the code is very long, you may need to scroll down a bit after clicking the preview element to land on the most accurate highlighted line.
- Live preview while editing HTML/CSS/JS
- Two-way highlight mapping between source and output; for very long code, the jump may need a small scroll to show the exact highlighted line.
- Formatting support for cleaner markup
- No signup and no installation required
Playground: features worth a quick read
Edit mode and two-way highlighting
By default, code and preview stay linked: click something in the preview to highlight the matching code, and click code to highlight the matching area in the preview. When you need uninterrupted typing or big paste jobs, click Edit to enter edit mode—it turns off highlight sync and jump-to-line so you can focus on editing.
Format
Format tidies the active tab (HTML, CSS, or JavaScript) with consistent indentation and line breaks so the file is easier to read, review, and share.
Expand all / Collapse all
Long files can fold regions in the editor. Expand all opens every folded section at once; Collapse all closes them so you can scan the outline or focus on one part.
What users say
Short notes from common use cases: debugging, cleanup, and teaching.
I use it when a snippet looks wrong in production. Seeing source and preview together cuts my debugging time a lot.
Alex M.
Front-end developer
"Our team uses it to clean generated HTML before committing. The formatted output is easier to review."
Jordan K.
Student / Using tool for 4 months
"I teach juniors with it because they can see markup changes reflected immediately in preview."
Sam T.
Designer / Using tool for 2 months
"Import, adjust, preview, export. The flow is simple and avoids opening three different tools."
Riley C.
Beginner / Using tool for 3 months
FAQ
Open the Playground
Paste code, preview output, format markup, and export clean HTML.
HTML Viewer Online
- Edit HTML, CSS, and JS in one place
- Preview output instantly while you type
- Format markup for cleaner review
- Import and export .html files
