Limits and specifications of the Live API


This page describes various limits and specifications for using the Live API and its models.

Session-related limits

For the Live API, a session refers to a persistent connection where input and output are streamed continuously over the same connection.

If the session exceeds any of the following limits, the connection is terminated.

  • Connection length is limited to around 10 minutes.

  • Session length depends on the input modalities:

    • Audio-only input sessions are limited to 15 minutes.
    • Video + audio input are limited to 2 minutes.

  • Session context window is limited to 128k tokens.

You'll receive a going away notification before the connection ends, allowing you to take further actions.

Learn more about managing sessions.

Rate limits

The Live API has rate limits for both concurrent sessions per Firebase project as well as tokens per minute (TPM).

  • Gemini Developer API:

  • Vertex AI Gemini API:

    • 1,000 concurrent sessions per Firebase project
    • 4M tokens per minute

Audio formats

The Live API supports the following audio formats:

  • Input audio format: Raw 16 bit PCM audio at 16kHz little-endian

  • Output audio format: Raw 16 bit PCM audio at 24kHz little-endian

  • Supported MIME types: audio/x-aac, audio/flac, audio/mp3, audio/m4a, audio/mpeg, audio/mpga, audio/mp4, audio/ogg, audio/pcm, audio/wav, audio/webm

To convey the sample rate of input audio, set the MIME type of each audio-containing Blob to a value like audio/pcm;rate=16000.

Video formats

The Live API expects a sequence of discrete image frames and supports video frames input at 1 frame per second (FPS).

  • Recommended input: native 768x768 resolution at 1 FPS.

  • Supported MIME types: video/x-flv, video/quicktime, video/mpeg, video/mpegs, video/mpg, video/mp4, video/webm, video/wmv, video/3gpp

Note that this specification makes the Live API unsuitable for use cases that require analyzing fast-changing video, such as play-by-play in high-speed sports.

Response voices

The Live API supports the following response voice options. For demos of what each voice sounds like, see Chirp 3: HD voices.

If you don't specify a response voice, the default is Puck.

Learn how to specify the response voice.

Zephyr -- Bright
Kore -- Firm
Orus -- Firm
Autonoe -- Bright
Umbriel -- Easy-going
Erinome -- Clear
Laomedeia -- Upbeat
Schedar -- Even
Achird -- Friendly
Sadachbia -- Lively 		Puck -- Upbeat
Fenrir -- Excitable
Aoede -- Breezy
Enceladus -- Breathy
Algieba -- Smooth
Algenib -- Gravelly
Achernar -- Soft
Gacrux -- Mature
Zubenelgenubi -- Casual
Sadaltager -- Knowledgeable 		Charon -- Informative
Leda -- Youthful
Callirrhoe -- Easy-going
Iapetus -- Clear
Despina -- Smooth
Rasalgethi -- Informative
Alnilam -- Firm
Pulcherrima -- Forward
Vindemiatrix -- Gentle
Sulafat -- Warm

Languages

The Live API supports the following languages. Learn how to influence the response language.

Language BCP-47 Code Language BCP-47 Code
Arabic (Egyptian) ar-EG German (Germany) de-DE
English (US) en-US Spanish (US) es-US
French (France) fr-FR Hindi (India) hi-IN
Indonesian (Indonesia) id-ID Italian (Italy) it-IT
Japanese (Japan) ja-JP Korean (Korea) ko-KR
Portuguese (Brazil) pt-BR Russian (Russia) ru-RU
Dutch (Netherlands) nl-NL Polish (Poland) pl-PL
Thai (Thailand) th-TH Turkish (Turkey) tr-TR
Vietnamese (Vietnam) vi-VN Romanian (Romania) ro-RO
Ukrainian (Ukraine) uk-UA Bengali (Bangladesh) bn-BD
English (India) en-IN & hi-IN bundle Marathi (India) mr-IN
Tamil (India) ta-IN Telugu (India) te-IN