> ## Documentation Index
> Fetch the complete documentation index at: https://docs.usecrow.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# Multi-Language Support

> Make the AI respond in your user's language

Pass a `language` prop to the widget and Crow handles the rest — the AI responds in that language and the welcome message is translated automatically.

**Example:** Your platform has users who speak Spanish, Japanese, and French. Set `language="es"` for Spanish users and the entire experience adapts — no prompt engineering needed.

***

## How It Works

```
1. You pass a language code (ISO 639-1) when embedding the widget
2. Crow translates the welcome message on the fly
3. A language instruction is injected into the AI's system prompt
4. The AI responds in the specified language for the entire conversation
```

When no language is passed (or `language="en"`), behavior is unchanged — fully backward compatible.

***

## Pass Language to Widget

<Tabs>
  <Tab title="Script Tag">
    Add `data-language` to the script tag:

    ```html theme={null}
    <script
      src="https://api.usecrow.org/static/crow-widget.js"
      data-api-url="https://api.usecrow.org"
      data-product-id="YOUR_PRODUCT_ID"
      data-language="es"
    ></script>
    ```

    | Attribute       | Required | Description                                      |
    | --------------- | -------- | ------------------------------------------------ |
    | `data-language` | No       | ISO 639-1 language code (e.g., `es`, `fr`, `ja`) |
  </Tab>

  <Tab title="React SDK">
    Pass the `language` prop:

    ```tsx theme={null}
    <CrowWidget
      productId="YOUR_PRODUCT_ID"
      apiUrl="https://api.usecrow.org"
      language="es"
    />
    ```

    ```tsx theme={null}
    <CrowCopilot
      productId="YOUR_PRODUCT_ID"
      apiUrl="https://api.usecrow.org"
      language="es"
      variant="floating"
    />
    ```

    | Prop       | Required | Description                                      |
    | ---------- | -------- | ------------------------------------------------ |
    | `language` | No       | ISO 639-1 language code (e.g., `es`, `fr`, `ja`) |
  </Tab>
</Tabs>

<Tip>
  You can set `language` dynamically based on the logged-in user's locale, browser settings, or any other runtime value. For example:

  ```tsx theme={null}
  const language = user.locale || navigator.language.split('-')[0];

  <CrowWidget language={language} ... />
  ```
</Tip>

***

## What Gets Translated

| Element                        | Behavior                                                              |
| ------------------------------ | --------------------------------------------------------------------- |
| **Welcome message**            | Translated automatically when the widget loads (uses a fast LLM call) |
| **AI responses**               | All replies are in the specified language for the entire conversation |
| **Error messages from the AI** | Also in the specified language                                        |
| **Widget UI chrome**           | Not translated (buttons, placeholders remain in English)              |

***

## Supported Languages

Crow supports the following ISO 639-1 codes:

| Code | Language    | Code | Language   | Code | Language   |
| ---- | ----------- | ---- | ---------- | ---- | ---------- |
| `af` | Afrikaans   | `hr` | Croatian   | `nl` | Dutch      |
| `am` | Amharic     | `hu` | Hungarian  | `no` | Norwegian  |
| `ar` | Arabic      | `hy` | Armenian   | `pa` | Punjabi    |
| `az` | Azerbaijani | `id` | Indonesian | `pl` | Polish     |
| `be` | Belarusian  | `is` | Icelandic  | `pt` | Portuguese |
| `bg` | Bulgarian   | `it` | Italian    | `ro` | Romanian   |
| `bn` | Bengali     | `ja` | Japanese   | `ru` | Russian    |
| `bs` | Bosnian     | `ka` | Georgian   | `si` | Sinhala    |
| `ca` | Catalan     | `kk` | Kazakh     | `sk` | Slovak     |
| `cs` | Czech       | `km` | Khmer      | `sl` | Slovenian  |
| `cy` | Welsh       | `kn` | Kannada    | `sq` | Albanian   |
| `da` | Danish      | `ko` | Korean     | `sr` | Serbian    |
| `de` | German      | `lo` | Lao        | `sv` | Swedish    |
| `el` | Greek       | `lt` | Lithuanian | `sw` | Swahili    |
| `en` | English     | `lv` | Latvian    | `ta` | Tamil      |
| `es` | Spanish     | `mk` | Macedonian | `te` | Telugu     |
| `et` | Estonian    | `ml` | Malayalam  | `th` | Thai       |
| `fa` | Persian     | `mn` | Mongolian  | `tl` | Filipino   |
| `fi` | Finnish     | `mr` | Marathi    | `tr` | Turkish    |
| `fr` | French      | `ms` | Malay      | `uk` | Ukrainian  |
| `ga` | Irish       | `my` | Burmese    | `ur` | Urdu       |
| `gl` | Galician    | `ne` | Nepali     | `uz` | Uzbek      |
| `gu` | Gujarati    |      |            | `vi` | Vietnamese |
| `he` | Hebrew      |      |            | `zh` | Chinese    |
| `hi` | Hindi       |      |            | `zu` | Zulu       |

Passing an unsupported code returns a `422` validation error.

***

## Behavior Details

| Scenario                  | Behavior                                                        |
| ------------------------- | --------------------------------------------------------------- |
| `language` not passed     | English (default) — no changes to current behavior              |
| `language="en"`           | English — no translation or prompt injection                    |
| `language="es"`           | Welcome message translated to Spanish, AI responds in Spanish   |
| Unsupported language code | `422` error returned by the API                                 |
| Welcome message is null   | The SDK default ("Hi! How can I help you today?") is translated |
| Translation fails         | Falls back to the original English text silently                |

***

## Troubleshooting

| Issue                            | Solution                                                                                                                           |
| -------------------------------- | ---------------------------------------------------------------------------------------------------------------------------------- |
| `422` error on chat              | Check the language code is a valid ISO 639-1 code from the table above                                                             |
| Welcome message still in English | Verify `data-language` / `language` prop is set and not `"en"`                                                                     |
| AI responds in wrong language    | Check the language code is correct — `zh` for Chinese, `pt` for Portuguese, etc.                                                   |
| Mixed languages in response      | This can happen if the user writes in a different language. The AI prioritizes the configured language but may adapt to user input |