All tools

CSS Style Tester

CSS

Write CSS and see it applied to sample HTML elements live

Write CSS rules and see them applied instantly to a set of representative sample elements (buttons, forms, text) rather than only imagining the effect or bouncing to a real project to test it. It's built around those built-in sample elements for quick feedback, so testing against your own custom markup specifically isn't the primary workflow here; check the tool's options if that's what you need. Standard CSS features work as-is against the live preview, including media queries, pseudo-classes like `:hover` and `:focus`, and custom properties, and you can resize your browser window while it's open to get a rough sense of responsive behavior, though there's no dedicated device-frame simulator for that. Nothing you write is sent anywhere: it's rendered and applied entirely client-side.

cssplaygroundpreviewsandboxlive

How to use CSS Style Tester

  • 1.Write CSS rules in the editor and see them applied live to a set of sample HTML elements (buttons, forms, text) to preview real-world effect.
  • 2.Test a new component style against multiple element types at once before copying the CSS into your actual project.
  • 3.Tweak hover, focus, and other pseudo-class styles and interact with the preview elements directly to confirm they behave as expected.

Frequently asked questions

Does it support custom HTML, or only the built-in sample elements?
It's built around a set of representative sample elements to give quick visual feedback — check the tool's options if you need to test against your own custom markup.
Is my CSS sent to a server?
No, styles are applied and rendered entirely in your browser.
Can I test responsive breakpoints?
You can resize your browser window while the preview is open to see how your CSS responds at different widths, though there's no dedicated device-frame simulator.
Does it support CSS features like `@media`, `:hover`, and custom properties?
Yes, standard CSS features including media queries, pseudo-classes, and custom properties (variables) all work since the CSS is applied as-is to the live preview.

Availability

This tool currently runs in the browser only — no REST API, SDK, or MCP equivalent yet.

Related tools

CSS Animation BuilderBuild CSS @keyframes animations with presets, live preview, and generated CSSCSSBorder RadiusVisual CSS border-radius builder with live preview and presetsCSSBox ShadowVisual CSS box-shadow builder with multiple layers and presetsCSS