Online HTML Editor
Write HTML and inspect the result in a sandboxed live preview without uploading your code.
HTML code editor and preview
How to use the HTML editor
Enter a complete HTML document or a small fragment in the editor. Live preview updates shortly after each change, or you can turn it off and use the Run preview button when working with a larger document.
The preview runs in an isolated iframe. Inline CSS is supported, which makes the tool useful for testing layouts, email fragments, semantic markup, tables and small components. JavaScript and external resources are intentionally blocked to keep previewed code separated from the site.
Use Full screen when you need more room to inspect responsive layout, then copy or download the original HTML when you are finished.
What an online HTML editor can and cannot validate
A browser preview shows how markup renders, but it is not a complete standards validator. A page can look correct while still containing accessibility problems, invalid nesting, missing labels or metadata issues.
Review heading order, image alternative text, form labels and keyboard behavior separately before publishing production HTML.
Common HTML preview use cases
The editor is useful for testing small HTML snippets, email-like fragments, tables, documentation examples, semantic structure and CSS layout ideas before moving them into a larger project.
Full-screen preview gives more room when checking spacing, typography and responsive behavior. Because the preview is sandboxed, it is intentionally closer to a safe inspection surface than a complete browser tab with unrestricted page behavior.
Why are scripts blocked?
Blocking scripts keeps pasted HTML separated from the GenericTools.dev page and reduces the risk of running untrusted code while previewing examples.
Can I use external CSS or images?
External network requests are blocked in the preview. Inline CSS and data images are better for quick local inspection on this page.