Dark & Light Theme Tester
Preview your UI color palette side-by-side in light mode and dark mode simultaneously. Customize background, text and accent brand colors, export ready-to-use CSS variables for dual theme websites.
Custom Theme Colors
Light Mode Palette
Dark Mode Palette
Light Mode Preview
Sample body paragraph text for website content display, readability test.
Secondary text description block for UI component testing.
Dark Mode Preview
Sample body paragraph text for website content display, readability test.
Secondary text description block for UI component testing.
Generated Dual Theme CSS
How To Use Dark & Light Theme Tester
This offline dual-theme preview tool lets front-end and UI designers test complete light and dark color schemes side by side. All color rendering and CSS generation run locally inside your browser without uploading any palette data to server.
- Customize background, body text and brand accent color separately for light and dark mode
- Live split-screen preview instantly updates after modifying any color value
- Test text readability, button contrast and overall visual balance of dual themes
- Export complete CSS custom properties for both light and dark mode in one block of code
- Copy full CSS snippet to directly integrate dark mode into your website stylesheet
Frequently Asked Questions
Yes, the split two-column layout displays light and dark previews simultaneously, you can easily compare text contrast and brand accent performance on both backgrounds.
It generates complete :root light theme variables and @media (prefers-color-scheme: dark) dark theme variables, fully compatible with all modern browsers.
All color previews and CSS code generation are calculated client-side only. No HEX values or theme data will leave your browser.