Tailwind CSS v4.3.3: CLI Polling Fix, Color Matching Improvements, and More

Tailwind CSS v4.3.3 is now available, bringing a range of fixes and improvements that enhance reliability, compatibility, and developer experience. This patch release focuses on edge cases in the CLI, color system, and build pipeline.

Key Changes

@tailwindcss/cli: Fixed support for --watch --poll[=ms] when filesystem events are unreliable or unavailable. This ensures polling mode works correctly for environments like Docker or network drives. (#20297)
Color canonicalization: Arbitrary hex colors in utilities like bg-[#fff] now match theme colors case-insensitively, so bg-[#FFF] correctly resolves to bg-white. (#20298)
Preflight: Prevented overriding Firefox's native iframe:focus-visible outline styles, preserving default accessibility behavior. (#20292)
JS plugins: theme('colors.foo') now resolves correctly when both --color-foo and --color-foo-bar CSS variables exist, fixing a namespace collision issue. (#20299)
Fractional opacity modifiers: Named shadow sizes like shadow-sm/12.5, text-shadow-sm/12.5, drop-shadow-sm/12.5, and inset-shadow-sm/12.5 now work with fractional opacity values, enabling finer visual control. (#20302)
Selector parsing: Selectors like [data-foo]div are now parsed as two separate selectors instead of one, fixing unintended styling. (#20303)
PostCSS rebuilds: @tailwindcss/postcss now rebuilds correctly when a preprocessor (e.g., Sass) changes the input CSS without modifying the file on disk. (#20310)
CSS nesting: Ensured CSS nesting is handled even when Lightning CSS is not run, such as in @tailwindcss/browser and Tailwind Play environments. (#20124)
Achromatic colors: Prevented achromatic theme colors (e.g., black, white, grays) from shifting hue when mixed in polar color spaces like oklch, maintaining their neutral appearance. (#20314)
Spacing optimization: --spacing(0) now optimizes to 0px instead of 0, ensuring compatibility as a length unit in calc(). (#20319)

Why This Matters

This release demonstrates the Tailwind team's commitment to addressing real-world edge cases that affect daily development workflows. From improved CLI polling reliability (critical for containerized setups) to more consistent color matching and safer default styles, v4.3.3 reduces friction and makes the framework more predictable across different environments and use cases.

Source: https://github.com/tailwindlabs/tailwindcss/releases/tag/v4.3.3