# General Translation Platform: resolveAliasLocale
URL: https://generaltranslation.com/en-US/docs/platform/core/reference/utility-functions/locales/resolve-alias-locale.mdx
---

title: resolveAliasLocale
description: Resolve a locale alias to the locale code used by a custom mapping without a GT instance. API reference for resolveAliasLocale.

---

[`resolveAliasLocale`](/docs/platform/core/reference/gt-class-methods/locales/resolve-alias-locale) is a standalone utility function from General Translation's Core library that converts a canonical locale code back to its alias locale code when a custom mapping is configured.

## Overview [#overview]

Import `resolveAliasLocale` directly from `generaltranslation` and call it with a locale code and a custom mapping. It does not require an API key or a [GT](/docs/platform/core/reference/gt-class/constructor) instance. For the instance-based equivalent, use the [`resolveAliasLocale`](/docs/platform/core/reference/gt-class-methods/locales/resolve-alias-locale) method on a [`GT`](/docs/platform/core/reference/gt-class/constructor) instance instead.

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

const customMapping = {
  'simplified-chinese': { code: 'zh-CN', name: 'Simplified Chinese' },
  'traditional-chinese': { code: 'zh-TW', name: 'Traditional Chinese' },
};

console.log(resolveAliasLocale('zh-CN', customMapping)); // 'simplified-chinese'
```

Signature:

```typescript
resolveAliasLocale(locale: string, customMapping?: CustomMapping): string
```

## How it works [#how-it-works]

- **Reverse lookup.** Converts a canonical locale code back to the user-facing alias defined in the [`customMapping`](/docs/platform/core/reference/types/custom-mapping).
- **Fallback.** Returns the original locale if no matching alias exists in the mapping.
- **Stateless.** Has no side effects.

## Parameters [#parameters]

| Parameter | Description | Type | Optional | Default |
| --- | --- | --- | --- | --- |
| [`locale`](#locale) | The canonical locale code to resolve to an alias. | `string` | No | — |
| [`customMapping`](#custom-mapping) | The custom mapping used to resolve the alias. | [`CustomMapping`](/docs/platform/core/reference/types/custom-mapping) | Yes | — |

### `locale` [#locale]

**Type** `string` · **Required**

The canonical locale code to resolve to an alias.

### `customMapping` [#custom-mapping]

**Type** [`CustomMapping`](/docs/platform/core/reference/types/custom-mapping) · **Optional**

The custom mapping used to resolve the alias. Without a mapping, the input locale is returned unchanged.

## Returns [#returns]

**Type** `string`

The alias locale code if a mapping exists, otherwise the original locale.

## Examples [#examples]

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

const customMapping = {
  'simplified-chinese': { code: 'zh-CN', name: 'Simplified Chinese' },
  'traditional-chinese': { code: 'zh-TW', name: 'Traditional Chinese' },
};

// Resolve canonical to alias
console.log(resolveAliasLocale('zh-CN', customMapping)); // 'simplified-chinese'
console.log(resolveAliasLocale('zh-TW', customMapping)); // 'traditional-chinese'

// Non-mapped locale returns the original
console.log(resolveAliasLocale('es-ES', customMapping)); // 'es-ES'
```

## Notes [#notes]

- Converts canonical locale codes back to user-friendly aliases.
- Returns the original locale if no mapping exists.
- Essential for displaying user-facing locale names.
- Works with custom locale mappings.
- Stateless function — no side effects.