About HTML Previewer
HTML Previewer renders a small HTML sample in a restricted browser sandbox so you can inspect structure and basic styling without uploading the source.
A sandbox preview is useful for isolated markup experiments, but it is not a full application test. Check external resources, browser differences, accessibility, CSP, and the integration environment before shipping HTML.
How to use this developer tool
- Paste a small HTML document into the editor.
- Preview the result and inspect the structure, styles, and visible text.
- Validate links, forms, accessibility, and script behavior in a controlled development environment rather than relying on this isolated preview.
Privacy and data handling
HTML is rendered locally in a restricted sandbox. Scripts and external resources are intentionally limited; do not use the preview to handle private documents or to assess untrusted code as if it were safe.
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Frequently asked questions
Does the preview execute scripts?
The preview is restricted to reduce the risk of arbitrary script execution. Use a controlled local development environment when testing application behavior.
Why are external styles or images missing?
The sandbox may block external resource access. Inline a small test style or inspect the final page in the environment where the resource is authorized.
Is the preview a security scanner?
No. It is a rendering aid, not a vulnerability assessment or a guarantee that the same HTML is safe in another application.