Chatbot Language Setup

ChatLab supports 90+ languages for text chat and 32 languages for voice conversations. You can configure your chatbot to respond in a single language, automatically detect the visitor's language, or run separate chatbots for each language section of your website.

Language settings overview

There are several language-related settings, each controlling a different aspect:

• Primary language (Settings > Role & Behavior) -- the language the chatbot uses for text chat replies
• Voice language (Settings > Voice Conversation) -- the default and additional languages used during voice conversations (ElevenLabs voice model only)
• Internal language (Settings > Model & Advanced) -- the language used for internal features like conversation summaries and AI Insights

Additionally, all predefined chatbot messages (welcome message, suggested questions, form labels) need to be translated manually in their respective settings sections.

Setting the primary language for text chat

Select your chatbot, click the Settings tab, then select Role & Behavior in the left sidebar.

The Primary language dropdown offers two modes:

• Auto Detect (default) -- the chatbot recognizes the visitor's language and responds in that same language automatically. This is the best choice for multilingual audiences.
• Specific language (e.g., English, Spanish, German) -- the chatbot uses the selected language by default. It will only switch if the visitor explicitly asks to use another language.

Click Save Changes after adjusting.

Setting the language for voice conversations

Voice language configuration is available in Settings > Voice Conversation. The behavior depends on which voice model you choose:

• ElevenLabs Voice -- uses a dedicated Language picker described below. The agent automatically switches voice and language to match what the caller speaks.
• GPT Realtime / Gemini Voice -- no language picker. Language follows the system prompt and the provider's built-in auto-detection. To bias these models toward a specific language, mention it in Role & Behavior (for example, "Always respond in Polish unless the caller speaks another language").

ElevenLabs Language picker

When the voice model is set to ElevenLabs Voice, a Language section appears right under the voice picker.

It contains two cards:

• Default language -- the language the agent starts the call in. Click the card to open a searchable list and pick one language.
• Additional languages -- extra languages the agent is allowed to switch into mid-call when it detects the caller speaking them. Click the card to open a multi-select list with Select all languages and search.

The Additional languages card shows preview flags and a summary like "Polish, German, French" or "Polish, German, French, & 29 more" so you can see your selection at a glance.

The 32 supported languages are: Arabic, Bulgarian, Chinese, Croatian, Czech, Danish, Dutch, English, Filipino, Finnish, French, German, Greek, Hindi, Hungarian, Indonesian, Italian, Japanese, Korean, Malay, Norwegian, Polish, Portuguese, Romanian, Russian, Slovak, Spanish, Swedish, Tamil, Turkish, Ukrainian, and Vietnamese.

Click Save Changes after adjusting. The next voice call will use the new language settings.

Translating chatbot messages

When you set a specific primary language, update all predefined chatbot messages to match. These messages are not translated automatically -- they need to be changed manually.

Key areas to update in Settings > Conversation:

• Welcome message -- the first message visitors see when the chat opens
• Suggested questions -- the conversation openers shown below the welcome message
• Placeholder for new message -- the input field placeholder text

Other sections to check:

• Settings > Appearance -- the chatbot tagline
• Settings > Lead Collection -- form labels and messages (if lead collection is enabled)
• Settings > Human Contact Form -- form labels and messages (if human support is enabled)
• Settings > Live Chat -- all live chat messages (if live chat is enabled)
• Settings > Consent & Privacy -- consent messages (if consent is required)
• Settings > Conversation -- widget header tooltip texts
• Settings > Voice Conversation -- voice welcome message and the message shown when a voice call ends

Using custom instructions for language control

If you need more control over language behavior, switch to custom instructions (Settings > Role & Behavior > click Enable custom role and behavior instructions). In your custom prompt, you can include language rules such as:

• "Always respond in Spanish, even if the user writes in another language"
• "Respond in the user's language, but default to French when unsure"
• "Never switch languages -- always respond in German"

You can write custom instructions in any language, or mix languages. For example, keeping technical terms in English while writing the rest in your target language works well.

For more details on custom instructions, see Bot behavior customization.

Setting the internal language

The internal language controls the language used for behind-the-scenes features that are visible only to you in the admin panel -- not to your visitors.

Navigate to Settings > Model & Advanced and find the Internal language section.

This setting affects:

• Conversation summaries -- the AI-generated summary of each conversation
• Client summaries -- the AI-generated profile of each returning visitor
• AI Conversation Insights -- the periodic AI analysis of conversation patterns

By default, the internal language matches the language of your admin interface. Change it if you want summaries and insights generated in a different language.

Language setup scenarios

Single-language website

Best for websites that serve one language audience.

1. Set Primary language to your website's language (Settings > Role & Behavior)
2. If voice is enabled with ElevenLabs, set the same language as the Default language (Settings > Voice Conversation) and leave Additional languages empty
3. Translate all chatbot messages to match (see Translating chatbot messages above)
4. Set Internal language to your preferred language (Settings > Model & Advanced)

The chatbot will still switch languages if a visitor explicitly asks, but defaults to your chosen language.

Single-language website with multilingual visitors

Best for websites in one language that occasionally receive visitors in other languages.

1. Set Primary language to Auto Detect (Settings > Role & Behavior)
2. For ElevenLabs voice, set the main language as Default language and add the most common visitor languages under Additional languages
3. Keep chatbot messages in your website's main language
4. Optionally add a custom instruction like: "Default to English, but switch to the visitor's language when they write in another language"

The chatbot will respond in the visitor's language while keeping predefined messages (welcome message, suggested questions) in your main language.

Multilingual website with one chatbot

Best for websites available in multiple languages but using a single chatbot.

1. Set Primary language to Auto Detect (Settings > Role & Behavior)
2. For ElevenLabs voice, pick the most common visitor language as Default language and add the rest under Additional languages (or use Select all languages)
3. Keep chatbot messages in your website's primary language
4. Train the chatbot with content -- avoid duplicating the same content in multiple languages (see Training tips for multilingual chatbots below)

Fully multilingual website with separate chatbots

Best for websites with distinct language sections (e.g., /en/, /de/, /fr/) where each section needs a fully localized experience.

1. Create a separate chatbot for each language
2. For each chatbot:
   • Set the appropriate Primary language
   • For ElevenLabs voice, set the matching Default language and leave Additional languages empty (or limit to a couple of fallbacks)
   • Translate all chatbot messages to that language
   • Train it only on content from that language section of your website
3. Go to Add to Website for each chatbot, copy the embed code, and paste it only in the matching language section of your website

This gives the most complete localized experience, with welcome messages, suggested questions, and all form labels in the correct language.

Training tips for multilingual chatbots

When training a chatbot that serves multiple languages, avoid duplicating the same content across languages. Here is why:

• Limited context window -- the AI can only use a limited amount of training data per response. Duplicate content in multiple languages wastes this capacity.
• Reduced answer quality -- when the same information exists in multiple languages, less room remains for diverse, useful knowledge.
• AI translates automatically -- the chatbot can use content trained in one language to answer questions in another language. For example, training data in English can be used to answer a question asked in Spanish.

When training on a multilingual website, select only the pages in your primary language and exclude translated duplicates. If certain content is unique to a specific language (region-specific information, language-specific promotions), include that content as well.

Frequently asked questions

Do my custom instructions need to be in a specific language?

Custom instructions work in any language. You can write them entirely in your target language, entirely in English, or mix languages. The important thing is that the instructions clearly describe the behavior you want. See Bot behavior customization for details.

Can the chatbot use training data in one language to answer in another?

Yes. The AI can use knowledge from one language to generate responses in another. However, nuanced or culturally specific content may not translate as accurately. For best results, provide training data in the languages your visitors use most frequently.

Can I train my chatbot with content in multiple languages?

Yes, but avoid duplicating the same content across languages. Focus on unique, language-specific information for each language instead of translating identical content multiple times.

Why don't I see a Language picker for GPT Realtime or Gemini voice models?

Those providers handle language detection internally. The voice agent will respond in the language the caller speaks. If you want to bias the agent toward a specific language, mention it in Settings > Role & Behavior (for example, "Always respond in Polish unless the caller speaks another language"). The Language picker is only shown for the ElevenLabs voice model, which exposes explicit default and additional language slots.