---
title: "tailwind-merge Breaking Changes on npm | Since.dev"
description: "What each tailwind-merge release removed, renamed or changed: 11 breaking changes in 1 version on npm, each with its source."
canonical_url: https://since.dev/packages/npm/tailwind-merge
last_updated: 2025-01-30
---

# tailwind-merge breaking changes

Every breaking API change we have recorded in tailwind-merge on npm: 11 breaking changes in 1 version. Below are its newest version, removals and renames first, each with its source.

Newest change January 30, 2025

## 3.0.0

11 breaking changes, first published January 30, 2025.

- **Removed** `Config.separator`  

Config.separator was removed in tailwind-merge 3.0.0 [npmjs.com](https://www.npmjs.com/package/tailwind-merge/v/3.0.0)
- **Removed** `ConfigExtension.separator`  

ConfigExtension.separator was removed in tailwind-merge 3.0.0 [npmjs.com](https://www.npmjs.com/package/tailwind-merge/v/3.0.0)
- **Removed** `validators.isLength`  

validators.isLength was removed in tailwind-merge 3.0.0 [npmjs.com](https://www.npmjs.com/package/tailwind-merge/v/3.0.0)
- **Signature changed** `Config.experimentalParseClassName`  

Was experimentalParseClassName?(param: ExperimentalParseClassNameParam): ExperimentalParsedClassName; now experimentalParseClassName?(param: ExperimentalParseClassNameParam): ParsedClassName. [npmjs.com](https://www.npmjs.com/package/tailwind-merge/v/3.0.0)
- **Signature changed** `ConfigExtension.experimentalParseClassName`  

Was experimentalParseClassName?(param: ExperimentalParseClassNameParam): ExperimentalParsedClassName; now experimentalParseClassName?(param: ExperimentalParseClassNameParam): ParsedClassName. [npmjs.com](https://www.npmjs.com/package/tailwind-merge/v/3.0.0)
- **Signature changed** `DefaultClassGroupIds`  

Was type DefaultClassGroupIds = 'accent' | 'align-content' | 'align-items' | 'align-self' | 'animate' | 'appearance' | 'aspect' | 'auto-cols' | 'auto-rows' | 'backdrop-blur' | 'backdrop-brightness' | 'backdrop-contrast' | 'backdrop-filter'... [npmjs.com](https://www.npmjs.com/package/tailwind-merge/v/3.0.0)
- **Signature changed** `DefaultThemeGroupIds`  

Was type DefaultThemeGroupIds = 'blur' | 'borderColor' | 'borderRadius' | 'borderSpacing' | 'borderWidth' | 'brightness' | 'colors' | 'contrast' | 'gap' | 'gradientColorStopPositions' | 'gradientColorStops' | 'grayscale' | 'hueRotate' |... [npmjs.com](https://www.npmjs.com/package/tailwind-merge/v/3.0.0)
- **Signature changed** `ExperimentalParseClassNameParam.parseClassName`  

Was parseClassName(className: string): ExperimentalParsedClassName; now parseClassName(className: string): ParsedClassName. [npmjs.com](https://www.npmjs.com/package/tailwind-merge/v/3.0.0)
- **Signature changed** `ExperimentalParsedClassName`  

Was interface ExperimentalParsedClassName; now interface ParsedClassName. [npmjs.com](https://www.npmjs.com/package/tailwind-merge/v/3.0.0)
- **Signature changed** `getDefaultConfig`  

Was const getDefaultConfig: () => {readonly cacheSize: 500; readonly separator: ":"; readonly theme: {readonly colors: readonly \[() => boolean\]; readonly spacing: readonly \[(value: string) => boolean, (value: string) => boolean\]; readonly... [npmjs.com](https://www.npmjs.com/package/tailwind-merge/v/3.0.0)

And 1 more in this version.

## Check your code

These are the changes. To see which of them reach your code, [scan a public repository](https://since.dev/scan.md), or have your coding agent call `check_code` with your manifest or lockfile over [MCP](https://since.dev/docs.md#mcp). [The API](https://since.dev/docs.md#api) reads every change in every version, not only the newest. On Team and up, a fix pull request opens for the changes that reach a connected repository. Nothing merges or deploys.

## Put your code on continuous management.

Scan a public repository now, or give your agent one line.

### See how out of date your code is.

[Scan a repository](https://since.dev/scan.md). Any public GitHub repository. No sign-in.

### Tell your agent what changed since it was trained.

`claude mcp add --transport http since https://api.since.dev/mcp`

---

Every page on this site as Markdown: https://since.dev/sitemap.md. For agents: https://since.dev/llms.txt.