# What changed in tailwind-merge

> 17 changes in tailwind-merge 2 to 3 from its official release notes, upgrade guides and advisories: 2 new APIs and options. Each one cited. Sources checked 2026-10-17. HTML: https://unstale.sh/npm/tailwind-merge/

To see which of these apply to a repository, run `npx @unstale/cli init` in it.

## tailwind-merge 3

### New APIs and options

- Theme getters now expose the referenced theme key so tooling can identify the theme scale without calling the getter. (3.7.0) — [release notes](https://github.com/dcastil/tailwind-merge/releases/tag/tailwind-merge%403.7.0)
- Adds a config option for Tailwind utilities where a slash is part of the full class name, such as named container queries. (3.6.0) — [release notes](https://github.com/dcastil/tailwind-merge/releases/tag/v3.6.0)

### Performance

- Performance optimizations make tailwind-merge more than 10% faster. (3.4.0) — [release notes](https://github.com/dcastil/tailwind-merge/releases/tag/v3.4.0)

### Behavior and default changes

- Adds support for readonly array values in the technology's accepted inputs. (3.6.0) — [release notes](https://github.com/dcastil/tailwind-merge/releases/tag/v3.6.0)
- Adds support for Tailwind CSS v4.3 utilities, including utilities whose full class name contains a slash. (3.6.0) — [release notes](https://github.com/dcastil/tailwind-merge/releases/tag/v3.6.0)
- Adds support for Tailwind CSS v4.2, allowing tailwind-merge to handle its class names and utilities. (3.5.0) — [release notes](https://github.com/dcastil/tailwind-merge/releases/tag/v3.5.0)

### Fixes and other changes

- Bare bg-conic now merges correctly with other background image classes. (3.7.0) — [release notes](https://github.com/dcastil/tailwind-merge/releases/tag/tailwind-merge%403.7.0)
- Arbitrary values using color() are now classified as colors instead of lengths. (3.7.0) — [release notes](https://github.com/dcastil/tailwind-merge/releases/tag/tailwind-merge%403.7.0)
- columns-auto now conflicts correctly with other columns classes. (3.7.0) — [release notes](https://github.com/dcastil/tailwind-merge/releases/tag/tailwind-merge%403.7.0)
- Container sizes such as inline-2xl now merge correctly. (3.7.0) — [release notes](https://github.com/dcastil/tailwind-merge/releases/tag/tailwind-merge%403.7.0)
- leading-none is no longer removed when the leading theme scale is overridden. (3.7.0) — [release notes](https://github.com/dcastil/tailwind-merge/releases/tag/tailwind-merge%403.7.0)
- Arbitrary values using light-dark() are now classified as colors instead of lengths. (3.7.0) — [release notes](https://github.com/dcastil/tailwind-merge/releases/tag/tailwind-merge%403.7.0)
- max-h-none is now included in the max-h class group. (3.7.0) — [release notes](https://github.com/dcastil/tailwind-merge/releases/tag/tailwind-merge%403.7.0)
- Axis shorthand px now overrides logical sides such as ps correctly. (3.7.0) — [release notes](https://github.com/dcastil/tailwind-merge/releases/tag/tailwind-merge%403.7.0)
- Deprecated shadow-inner is now classified as a shadow instead of a shadow color. (3.7.0) — [release notes](https://github.com/dcastil/tailwind-merge/releases/tag/tailwind-merge%403.7.0)
- Prevents arbitrary font-family and font-weight values from merging incorrectly. (3.4.1) — [release notes](https://github.com/dcastil/tailwind-merge/releases/tag/v3.4.1)

## tailwind-merge 2

### Fixes and other changes

- Arbitrary values using color-mix are now detected as colors by tailwind-merge. (2.6.1) — [release notes](https://github.com/dcastil/tailwind-merge/releases/tag/v2.6.1)