# Migration (https://www.tailwind-variants.org/docs/migration)

Upgrade guides for moving between Tailwind Variants major versions, including v2 to v3 and the lite build split.

## To v3.3.0
### Drop `tailwind-merge` for TV
Conflict resolution ships in the default build. Install only Tailwind Variants unless your app calls `tailwind-merge` directly:

```diff
- npm i tailwind-variants tailwind-merge
+ npm i tailwind-variants
```

Keep `tailwind-merge` if you still use `twMerge`, `extendTailwindMerge`, or similar elsewhere.

### Slots empty object
Passing `slots: {}` enables slot mode with an implicit `base` slot. Omit `slots` when you want a plain string return.

```ts
// Slot mode — returns { base: () => string }
const x = tv({ slots: {}, base: 'p-4' });

// String mode — omit slots
const y = tv({ base: 'p-4' });
```

### `cn` → `cnMerge` for config
The v3.2.2 split still applies:

```ts
// Before
cn('px-2', 'px-4')({ twMerge: false });

// After
cnMerge('px-2', 'px-4')({ twMerge: false });
cn('px-2', 'px-4'); // string, default merge
```

### Extended types
Extended component metadata now reflects merged variants, slots, and keys at runtime. Slotted components include the implicit `base` slot in types.

***

## v3.2.0 → v3.2.2
### `cn` returns a string
`cn` no longer accepts a config callback. Use `cnMerge` for custom merge behavior.

```ts
import { cn, cnMerge } from 'tailwind-variants';

cn('px-2', 'px-4'); // => "px-4"
cnMerge('px-2', 'px-4')({ twMerge: false }); // => "px-2 px-4"
```

***

## v3.1.1 → v3.2.0
### Replace `cnBase` with `cx`
```diff
- import { cnBase } from 'tailwind-variants';
+ import { cx } from 'tailwind-variants';

- cnBase('flex gap-2', className);
+ cx('flex gap-2', className);
```

### `cn` defaults to merge
On the default build, `cn` resolves conflicting Tailwind classes automatically.

***

## v2 → v3
### Two builds
```ts
// Default — conflict resolution included (v3.3+)
import { tv, cn, cx } from 'tailwind-variants';

// Lite — no merge, ~80% smaller
import { tv, cx } from 'tailwind-variants/lite';
```

### Removed APIs
* `responsiveVariants` — use Tailwind responsive prefixes in class strings ([Responsive](https://www.tailwind-variants.org/docs/responsive))
* `withTv` — use `tv` directly
* Lazy merge loading — replaced by explicit default vs lite builds

### Performance
v3 is significantly faster for merge operations. The default build includes merge; lite skips it entirely.

See [Class Resolution](https://www.tailwind-variants.org/docs/class-resolution) and [Releases](https://www.tailwind-variants.org/docs/releases) for v3.3.0 details.