WEBSITE THEME DOCTOR · 100% BROWSER

See your website before & after.

Bring local HTML and CSS, review proposed color changes, compare isolated previews and export an implementation kit. No uploads, no accounts, no automatic edits to your source.

Start your audit Open CSS Migration Lab

Sandboxed static previews Per-use approvals Optional IndexedDB projects Downloadable change kit

01 / OPEN LOCAL SOURCE

Import static HTML + CSS

Choose separate .html/.css files or a ZIP containing them. The preview is isolated; scripts, remote resources and active forms cannot run.

Select HTML, CSS or a website ZIPDrop files here or click to browse · ZIP, HTML, CSSMax 12 MB ZIP · 6 MB CSS · 1 MB per HTML. Source ZIPs need a generated HTML page for visual preview.

TRANSPARENT LIMITATIONS

Built for useful, controlled decisions

Only explicit supported opaque CSS colors are mapped. Imported HTML is sanitized into a sandboxed no-script/no-same-origin iframe with a restrictive Content Security Policy; stylesheets may still contain complex rules, so preview files only from sources you trust. External assets, imported stylesheets, JavaScript rendering, inherited styles, all user interface states and dynamic routes cannot be recreated reliably. Safe inline styles and small embedded data images may display, but inline declarations are not included in the migration inventory. Browser-only tools support safe review, not production certification. Always test your original application after applying exports.

Also test text over hero photos in the Image Contrast Lab →