# generaltranslation: General Translation Core SDK: isSameDialect
URL: https://generaltranslation.com/en-US/docs/core/functions/locales/is-same-dialect.mdx
---
title: isSameDialect
description: API reference for the isSameDialect function
---

## Overview

The `isSameDialect` function checks if multiple BCP-47 locale codes represent the same dialect without requiring a GT class instance.


---

## Reference

### Parameters

<TypeTable
  type={{
    "...locales": {
      type: '(string | string[])[]',
      optional: false,
    }
  }}
/>

### Returns

`boolean` - `true` if all locale codes represent the same dialect

---

## Examples

```typescript
import { isSameDialect } from 'generaltranslation';

// Same dialect checks
console.log(isSameDialect('en-US', 'en-US')); // true
console.log(isSameDialect('en', 'en-US')); // true (base language matches regional)
console.log(isSameDialect('en-US', 'en-GB')); // false (different regions)
console.log(isSameDialect('en-US', 'es-ES')); // false (different languages)
```


---

## Notes

- Considers base languages as parents of regional variants
- Regional variants must match exactly
- Essential for locale fallback logic
- Accepts flexible input formats
- No external dependencies

## Next steps

- Use GT class method [`isSameDialect`](/docs/core/class/methods/locales/is-same-dialect)
- Compare languages with [`isSameLanguage`](/docs/core/functions/locales/is-same-language)