# types.isSplitSize

- **Module:** types
- **Package:** libtmux
- **Language:** TypeScript
- **Kind:** function
- **Source:** https://github.com/libtmux/libtmux-ts/blob/3fe1ca654b81b8cbf4a13b777a001a3298c87a6f/packages/libtmux/src/types.ts#L218
- **Page:** https://libtmux.org/en/ts/latest/reference/types-issplitsize/

```
types.isSplitSize(value: : unknown) -> value is SplitSize
```

Test whether a value is valid tmux split geometry.

## Example

```ts
import { isSplitSize } from "libtmux";
const value: unknown = "30%";
const size = isSplitSize(value) ? value : undefined;
```