Add support for Tailwind CSS v4.2

[dcastil]

Release: https://github.com/tailwindlabs/tailwindcss/releases/tag/v4.2.0

Changes to check

Added

• Add mauve, olive, mist, and taupe color palettes to the default theme (#19627)
• Add @tailwindcss/webpack package to run Tailwind CSS as a webpack plugin (#19610)
• Add pbs-* and pbe-* utilities for padding-block-start and padding-block-end (#19601)
• Add mbs-* and mbe-* utilities for margin-block-start and margin-block-end (#19601)
• Add scroll-pbs-* and scroll-pbe-* utilities for scroll-padding-block-start and scroll-padding-block-end (#19601)
• Add scroll-mbs-* and scroll-mbe-* utilities for scroll-margin-block-start and scroll-margin-block-end (#19601)
• Add border-bs-* and border-be-* utilities for border-block-start and border-block-end (#19601)
• Add inline-*, min-inline-*, max-inline-* utilities for inline-size, min-inline-size, and max-inline-size (#19612)
• Add block-*, min-block-*, max-block-* utilities for block-size, min-block-size, and max-block-size (#19612)
• Add inset-s-*, inset-e-*, inset-bs-*, inset-be-* utilities for inset-inline-start, inset-inline-end, inset-block-start, and inset-block-end (#19613)
• Add font-features-* utility for font-feature-settings (#19623)

Fixed

• Prevent double @supports wrapper for color-mix values (#19450)
• Allow whitespace around @source inline() argument (#19461)
• Emit comment when source maps are saved to files when using @tailwindcss/cli (#19447)
• Detect utilities containing capital letters followed by numbers (#19465)
• Fix class extraction for Rails' strict locals (#19525)
• Align @utility name validation with Oxide scanner rules (#19524)
• Fix infinite loop when using @variant inside @custom-variant (#19633)
• Allow multiples of .25 in aspect-* fractions (e.g. aspect-8.5/11) (#19688)
• Ensure changes to external files listed via @source trigger a full page reload when using @tailwindcss/vite (#19670)
• Improve performance of Oxide scanner in bigger projects by reducing file system walks (#19632)
• Ensure import aliases in Astro v5 work without crashing when using @tailwindcss/vite (#19677)
• Allow escape characters in @utility names to improve support with formatters such as Biome (#19626)
• Fix incorrect canonicalization results when canonicalizing multiple times (#19675)
• Add .jj to default ignored content directories (#19687)

Deprecated

• Deprecate start-* and end-* utilities in favor of inline-s-* and inline-e-* utilities (#19613)

[github-actions]

Metrics report

At head commit 7a4cacf and base commit d2bbc29 at 2026-02-18T23:33:18.541Z

Size

Export	Size original	Size minified	Size minified and Brotli compressed
tailwind-merge esm	100.18 kB +5.1% 🔴	27.24 kB +4.0% 🔴	7.08 kB +1.8% 🔴
› extendTailwindMerge	99.40 kB +5.1% 🔴	26.53 kB +4.2% 🔴	6.90 kB +3.0% 🔴
› getDefaultConfig	80.02 kB +6.5% 🔴	21.38 kB +5.2% 🔴	5.10 kB +4.2% 🔴
› twMerge	97.08 kB +5.3% 🔴	25.68 kB +4.3% 🔴	6.66 kB +1.9% 🔴
› validators	4.95 kB +0.4% 🔴	1.85 kB +1.1% 🔴	0.76 kB +0.5% 🔴
tailwind-merge cjs	100.44 kB +5.1% 🔴	33.66 kB +3.3% 🔴	7.57 kB +3.3% 🔴
tailwind-merge/es5 esm	106.19 kB +4.9% 🔴	29.37 kB +4.0% 🔴	7.37 kB +2.4% 🔴
› extendTailwindMerge	104.95 kB +5.0% 🔴	28.66 kB +4.1% 🔴	7.15 kB +3.0% 🔴
› getDefaultConfig	82.77 kB +6.4% 🔴	22.68 kB +5.2% 🔴	5.15 kB +2.5% 🔴
› twMerge	102.05 kB +5.1% 🔴	27.59 kB +4.3% 🔴	6.93 kB +2.7% 🔴
› validators	6.70 kB +0.3% 🔴	2.46 kB +0.8% 🔴	0.82 kB -0.2% 🟢
tailwind-merge/es5 cjs	106.45 kB +4.9% 🔴	35.82 kB +3.3% 🔴	7.72 kB +1.6% 🔴

All size metrics

Export	Size original	Size minified	Size minified and Brotli compressed
tailwind-merge esm	100.18 kB +5.1% 🔴	27.24 kB +4.0% 🔴	7.08 kB +1.8% 🔴
› createTailwindMerge	17.11 kB 0%	4.25 kB 0%	1.62 kB 0%
› extendTailwindMerge	99.40 kB +5.1% 🔴	26.53 kB +4.2% 🔴	6.90 kB +3.0% 🔴
› fromTheme	0.27 kB 0%	0.09 kB 0%	0.08 kB 0%
› getDefaultConfig	80.02 kB +6.5% 🔴	21.38 kB +5.2% 🔴	5.10 kB +4.2% 🔴
› mergeConfigs	2.20 kB 0%	0.80 kB 0%	0.27 kB 0%
› twJoin	1.18 kB 0%	0.24 kB 0%	0.16 kB 0%
› twMerge	97.08 kB +5.3% 🔴	25.68 kB +4.3% 🔴	6.66 kB +1.9% 🔴
› validators	4.95 kB +0.4% 🔴	1.85 kB +1.1% 🔴	0.76 kB +0.5% 🔴
tailwind-merge cjs	100.44 kB +5.1% 🔴	33.66 kB +3.3% 🔴	7.57 kB +3.3% 🔴
tailwind-merge/es5 esm	106.19 kB +4.9% 🔴	29.37 kB +4.0% 🔴	7.37 kB +2.4% 🔴
› createTailwindMerge	19.26 kB 0%	4.86 kB 0%	1.77 kB 0%
› extendTailwindMerge	104.95 kB +5.0% 🔴	28.66 kB +4.1% 🔴	7.15 kB +3.0% 🔴
› fromTheme	0.25 kB 0%	0.11 kB 0%	0.08 kB 0%
› getDefaultConfig	82.77 kB +6.4% 🔴	22.68 kB +5.2% 🔴	5.15 kB +2.5% 🔴
› mergeConfigs	2.45 kB 0%	0.87 kB 0%	0.29 kB 0%
› twJoin	1.21 kB 0%	0.30 kB 0%	0.18 kB 0%
› twMerge	102.05 kB +5.1% 🔴	27.59 kB +4.3% 🔴	6.93 kB +2.7% 🔴
› validators	6.70 kB +0.3% 🔴	2.46 kB +0.8% 🔴	0.82 kB -0.2% 🟢
tailwind-merge/es5 cjs	106.45 kB +4.9% 🔴	35.82 kB +3.3% 🔴	7.72 kB +1.6% 🔴

[codspeed-hq]

Merging this PR will improve performance by 12.83%

⚡ 1 improved benchmark
✅ 6 untouched benchmarks

Performance Changes

	Benchmark	BASE	HEAD	Efficiency
⚡	init	4 ms	3.5 ms	+12.83%

---

_{Comparing feature/add-support-for-tailwind-css-v4.2 (7a4cacf) with main (d2bbc29)}

[dcastil]

Documenting merging behavior between logical and directional properties here.

We can't merge logical properties with directional properties very well because the logical properties depend on the writing mode.

It is probably known that *-inline-start will map to the left in languages that go from left to right and to the right in languages that go from right to left. But it can also map to the top, so we can't even set a conflict with the class group covering the x axis.

This is how I'll implement it for now.

But I see that in the majority of cases, tailwind-merge is used in left-to-right languages and it would be a benefit if tailwind-merge would properly merge logical with directional properties. Maybe it will be worth adding a config that sets them in conflict in the future.

[github-actions]

This was addressed in release v3.4.1-dev.6c1f77ca717df7d2685eb783c568ef7696148171.

[github-actions]

This was addressed in release v3.5.0.