Add support for Tailwind CSS v4.3

[dcastil]

Release: https://github.com/tailwindlabs/tailwindcss/releases/tag/v4.3.0

Changes to check

Added

• Add @container-size utility (#18901)
• Add scrollbar-{auto,thin,none} utilities for scrollbar-width, and scrollbar-thumb-* / scrollbar-track-* color utilities for scrollbar-color (#19981, #20019)
• Add scrollbar-gutter-* utilities (#20018)
• Add zoom-* utilities (#20020)
• Add tab-* utilities (#20022)
• Allow using @variant with stacked variants (e.g. @variant hover:focus { … }) (#19996)
• Allow using @variant with compound variants (e.g. @variant hover, focus { … }) (#19996)
• Support --default(…) in --value(…) and --modifier(…) for functional @utility definitions (#19989)

Fixed

• Ensure @plugin resolves package JavaScript entries instead of browser CSS entries when using @tailwindcss/vite (#19949)
• Fix relative @import and @plugin paths resolving from the wrong directory when using @tailwindcss/vite (#19965)
• Ensure CSS files containing @variant are processed by @tailwindcss/vite (#19966)
• Resolve imports relative to base when result.opts.from is not provided when using @tailwindcss/postcss (#19980)
• Canonicalization: preserve significant _ whitespace in arbitrary values (#19986)
• Canonicalization: add parentheses when removing whitespace from arbitrary values would hurt readability (e.g. w-[calc(100%---spacing(60))] → w-[calc(100%-(--spacing(60)))]) (#19986)
• Canonicalization: preserve the original unit in arbitrary values instead of normalizing to base units (e.g. -mt-[20in] → mt-[-20in], not mt-[-1920px]) (#19988)
• Canonicalization: migrate arbitrary :has() variants from [&:has(…)] to has-[…] (#19991)
• Upgrade: don’t migrate inline style attributes (e.g. style="flex-grow: 1" → style="flex-grow: 1", not style="grow: 1") (#19918)
• Allow multiple @utility definitions with the same name but different value types (#19777)
• Export missing PluginWithConfig type from tailwindcss/plugin to fix errors when inferring plugin config types (#19707)
• Ensure start and end legacy utilities without values do not generate CSS (#20003)
• Ensure --value(…) is required in functional @utility definitions (#20005)
• Canonicalization: preserve required whitespace around operators in negated arbitrary values (e.g. -left-[(var(--a)+var(--b))]) (#20011)

[github-actions]

Metrics report

At head commit 12d4f91 and base commit 2b1fdc2 at 2026-05-09T23:09:15.475Z

Size

Export	Size original	Size minified	Size minified and Brotli compressed
tailwind-merge esm	103.09 kB +2.9% 🔴	28.20 kB +3.5% 🔴	7.34 kB +3.7% 🔴
› createTailwindMerge	17.96 kB +4.9% 🔴	4.50 kB +5.8% 🔴	1.71 kB +5.7% 🔴
› extendTailwindMerge	102.29 kB +2.9% 🔴	27.46 kB +3.5% 🔴	7.08 kB +2.5% 🔴
› getDefaultConfig	81.90 kB +2.3% 🔴	21.98 kB +2.8% 🔴	5.27 kB +3.3% 🔴
› mergeConfigs	2.36 kB +7.4% 🔴	0.89 kB +11.4% 🔴	0.29 kB +9.8% 🔴
› twMerge	99.81 kB +2.8% 🔴	26.52 kB +3.3% 🔴	6.91 kB +3.8% 🔴
› validators	5.25 kB +6.2% 🔴	2.05 kB +10.6% 🔴	0.84 kB +10.0% 🔴
tailwind-merge cjs	103.35 kB +2.9% 🔴	34.86 kB +3.6% 🔴	7.79 kB +2.8% 🔴
tailwind-merge/es5 esm	109.24 kB +2.9% 🔴	30.36 kB +3.4% 🔴	7.60 kB +3.2% 🔴
› createTailwindMerge	20.19 kB +4.8% 🔴	5.13 kB +5.4% 🔴	1.86 kB +4.7% 🔴
› extendTailwindMerge	107.96 kB +2.9% 🔴	29.63 kB +3.4% 🔴	7.35 kB +2.8% 🔴
› getDefaultConfig	84.69 kB +2.3% 🔴	23.29 kB +2.7% 🔴	5.30 kB +2.9% 🔴
› mergeConfigs	2.61 kB +6.7% 🔴	0.96 kB +10.5% 🔴	0.30 kB +3.0% 🔴
› twMerge	104.90 kB +2.8% 🔴	28.47 kB +3.2% 🔴	7.16 kB +3.4% 🔴
› validators	7.06 kB +5.5% 🔴	2.68 kB +8.6% 🔴	0.87 kB +6.1% 🔴
tailwind-merge/es5 cjs	109.50 kB +2.9% 🔴	37.05 kB +3.4% 🔴	8.05 kB +4.3% 🔴

All size metrics

Export	Size original	Size minified	Size minified and Brotli compressed
tailwind-merge esm	103.09 kB +2.9% 🔴	28.20 kB +3.5% 🔴	7.34 kB +3.7% 🔴
› createTailwindMerge	17.96 kB +4.9% 🔴	4.50 kB +5.8% 🔴	1.71 kB +5.7% 🔴
› extendTailwindMerge	102.29 kB +2.9% 🔴	27.46 kB +3.5% 🔴	7.08 kB +2.5% 🔴
› fromTheme	0.27 kB 0%	0.09 kB 0%	0.08 kB 0%
› getDefaultConfig	81.90 kB +2.3% 🔴	21.98 kB +2.8% 🔴	5.27 kB +3.3% 🔴
› mergeConfigs	2.36 kB +7.4% 🔴	0.89 kB +11.4% 🔴	0.29 kB +9.8% 🔴
› twJoin	1.18 kB 0%	0.24 kB 0%	0.16 kB 0%
› twMerge	99.81 kB +2.8% 🔴	26.52 kB +3.3% 🔴	6.91 kB +3.8% 🔴
› validators	5.25 kB +6.2% 🔴	2.05 kB +10.6% 🔴	0.84 kB +10.0% 🔴
tailwind-merge cjs	103.35 kB +2.9% 🔴	34.86 kB +3.6% 🔴	7.79 kB +2.8% 🔴
tailwind-merge/es5 esm	109.24 kB +2.9% 🔴	30.36 kB +3.4% 🔴	7.60 kB +3.2% 🔴
› createTailwindMerge	20.19 kB +4.8% 🔴	5.13 kB +5.4% 🔴	1.86 kB +4.7% 🔴
› extendTailwindMerge	107.96 kB +2.9% 🔴	29.63 kB +3.4% 🔴	7.35 kB +2.8% 🔴
› fromTheme	0.25 kB 0%	0.11 kB 0%	0.08 kB 0%
› getDefaultConfig	84.69 kB +2.3% 🔴	23.29 kB +2.7% 🔴	5.30 kB +2.9% 🔴
› mergeConfigs	2.61 kB +6.7% 🔴	0.96 kB +10.5% 🔴	0.30 kB +3.0% 🔴
› twJoin	1.21 kB 0%	0.30 kB 0%	0.18 kB 0%
› twMerge	104.90 kB +2.8% 🔴	28.47 kB +3.2% 🔴	7.16 kB +3.4% 🔴
› validators	7.06 kB +5.5% 🔴	2.68 kB +8.6% 🔴	0.87 kB +6.1% 🔴
tailwind-merge/es5 cjs	109.50 kB +2.9% 🔴	37.05 kB +3.4% 🔴	8.05 kB +4.3% 🔴

[codspeed-hq]

Merging this PR will not alter performance

✅ 7 untouched benchmarks

---

_{Comparing feature/add-support-for-tailwind-css-v4.3 (12d4f91) with main (2b1fdc2)}

[github-actions]

This was addressed in release v3.5.0-dev.890d232af59d1c86161d88d57cf0f46ebfe3f380.

[github-actions]

This was addressed in release v3.6.0.