HTML Viewer
About the HTML Viewer
The HTML Viewer is the tool I reach for when someone sends me an HTML file and I want to see what it actually renders like — without saving it locally, without creating a new project, without any setup. Just paste, preview, understand.
It's also invaluable for inspecting HTML email templates. Email clients are notoriously inconsistent renderers, but getting a quick visual preview of the structure helps spot obvious layout issues before sending to an ESP for full cross-client testing. I use it constantly for reviewing pull requests that include template changes.
Features
- Live rendered preview — see exactly how the browser renders your HTML
- Safe sandboxed iframe — rendered in an isolated context, no script execution risk
- Real-time update — preview refreshes as you type or paste
- Full document support — works with complete HTML pages including
<head> - Fragment support — also previews HTML snippets without a full document wrapper
- No installation — no browser extensions or local servers needed
When a Preview Tells You More Than a Validator
Validation tells you if the HTML is structurally correct. Preview tells you if it looks right. These are different things. An HTML table can be perfectly valid but render completely broken due to a missing colspan attribute or mismatched row lengths. A form can be valid HTML but have labels that don't visually align with their inputs. Only a live preview reveals these issues.
I recommend a workflow of: validate structure first, beautify for readability, then preview the final result. Together with the validator and beautifier, the viewer completes a full HTML review toolkit.