Google launches Gemini 3.5 Transcribe with live transcription, Smart formatting, and support for 85+ languages

Google's new speech-to-text models cover both real-time and recorded audio, with features like correction handling, multilingual switching, custom vocabulary, speaker separation, and timestamps.

By Google Blog / Gemini API documentation08-27 · 10 min read
Product launch · XiaoHu Explains
One-minute overview
  • Google has released two variants: Gemini 3.5 Transcribe Live for real-time audio and Gemini 3.5 Transcribe for recorded files.
  • Key features include Smart automatic formatting, support for 85+ languages, multilingual switching, custom vocabulary, speaker separation, and timestamps.
  • Google reports a streaming WER of 4.0% and a non-streaming WER of 2.6%; both models are currently in public preview.

Google has released two new speech-to-text models: Gemini 3.5 Transcribe Live and Gemini 3.5 Transcribe. The former handles real-time speech, while the latter processes pre-recorded audio files.

Both models support a Smart mode, multilingual transcription, custom vocabulary, and speech recognition in noisy environments. The recorded version also offers speaker diarization and word-level timestamps. Both are now available in Public Preview via the Gemini API and Vertex AI, and can also be tried out in Google AI Studio.

Two models: one for live speech, one for recorded files

Gemini 3.5 Transcribe Live has the model ID gemini-3.5-transcribe-live. It receives audio through a WebSocket connection over the Live API and is designed for sub-second responses, making it suitable for real-time captions, live streaming transcription, phone assistants, and voice agents.

The Live version caps each session at 10 minutes. It doesn't support speaker diarization or word-level timestamps, only phrase-level timing information. For longer meetings, apps need to chain sessions together, or hand the recording to the recorded version once it's finished.

Gemini 3.5 Transcribe has the model ID gemini-3.5-transcribe. It processes uploaded recordings through the Interactions API and is optimized for a lower final word error rate, while also supporting speaker diarization, word-level timestamps, and more complete transcription output.

Recordings can be up to 1 hour long. If speaker diarization or word-level timestamps are enabled, the limit drops to 30 minutes per file. The official docs state that up to 8 speakers are supported, though anything beyond 3 is still experimental.

Google AI Studio offers hands-on experiences for both live and recorded transcription. Developers can upload their own meeting, call, or interview recordings to decide which model fits their needs.

Key features: Smart cleanup, multilingual support, custom vocabulary, and annotations

Smart mode tidies up spoken content

Standard verbatim transcription keeps every "um," "uh," repeated phrase, and false start. Smart mode removes filler words, merges self-corrections, and reformats the text to reflect the final intended meaning.

In the ordering demo below, the speaker first asks for a large hazelnut latte, then switches to caramel, cancels an extra shot, changes the ice level, and finally downsizes from large to medium. The Smart output only keeps the final confirmed order.

OFFICIAL DEMO · BILINGUAL
Official side-by-side: the verbatim transcript preserves the editing process, while Smart output keeps only the final order. The video has embedded bilingual subtitles.

Download bilingual video

Smart mode is well suited for dictating messages, emails, notes, and forms. If the use case requires preserving every utterance exactly as spoken, verbatim transcription is the way to go.

Over 85 languages with seamless switching

The models support more than 85 languages. Speakers can switch languages mid-sentence without manually specifying a language in advance.

The following demo cycles through English, Spanish, and Hindi, and also tests recognition of alphanumeric combinations.

OFFICIAL DEMO · BILINGUAL
Official demo: English, Spanish, and Hindi switching in sequence, with an alphanumeric string thrown in. The video has embedded bilingual subtitles.

Download bilingual video

Google says both live and recorded versions support multilingual transcription, but actual performance will still vary based on accent, recording quality, background noise, and language combinations.

Add custom terms: jargon, names, product names, and code

Developers can supply custom vocabulary to help the model recognize company names, product names, industry terms, people's names, and identifiers. The docs allow up to 1000 terms, though Google recommends keeping the most important ones under 100.

The live demo below incorporates background noise, custom terms like Neurowave and Server ID B742X, plus switching between English and Czech.

OFFICIAL DEMO · BILINGUAL
Official demo: Neurowave, Server ID B742X, Jiskra, and switching between English and Czech. A single demo can't represent every noisy environment.

Download bilingual video

This demo shows these features can be combined, but it doesn't guarantee identical results across all noise levels and accents.

The recorded version supports speaker diarization and word-level timestamps

The recorded version can distinguish between different speakers and return the time position for each word. These features are useful for meeting minutes, customer service quality reviews, interview subtitles, and scenarios where replaying the original audio is necessary.

Smart mode cannot be used together with speaker diarization or word-level timestamps. Smart mode removes words and merges corrections, while word-level timestamps require output that stays aligned with the source audio. The docs also warn that enabling word-level timestamps may degrade transcription quality.

Official benchmark data: 4.0% streaming WER, 2.6% non-streaming WER

In Google's overall English transcription tests, the real-time streaming model achieved a word error rate (WER) of 4.0%, while the recorded non-streaming model hit 2.6%. A lower WER means fewer words were substituted, dropped, or added.

GOOGLE BENCHMARK · LOWER WER IS BETTER
Google 官方整体英语转写 WER 对比图
Google reports: Live streaming WER 4.0%, File non-streaming WER 2.6%. Lower WER is better.

On the multilingual FLEURS benchmark, the live version scored a WER of 5.50%, and the recorded version 5.04%. Both sets of numbers show that processing the full audio yields lower error rates, while the live version prioritizes speed.

GOOGLE BENCHMARK · LOWER WER IS BETTER
Google 官方 FLEURS 多语转写 WER 对比图
Google reports: On FLEURS, Live WER is 5.50% and File WER is 5.04%.

Compared with Chirp 3, Google also claims that Gemini 3.5 Transcribe reduces the time from audio end to final text by 70%. This is a relative improvement in finalization time, not a 70% reduction in error rate. These figures come from Google's release materials, and the article doesn't provide enough information for outsiders to fully replicate the experiments, so real-world results will need to be tested with your own recordings.

Already integrated into Gboard, Gemini macOS, Antigravity, and AI Studio

Google is rolling out these transcription models across its own input tools and developer products.

Gboard Rambler

Rambler is the dictation feature in Gboard. Users can speak naturally, pause, and correct themselves, and the system turns it all into a polished message ready to send.

OFFICIAL DEMO · BILINGUAL
Gboard Rambler demo: dates, places, and phrasing get revised repeatedly, but the final output keeps only the intended message.

Download bilingual video

This demo directly shows Smart mode in action on mobile input: after the user changes a date, restaurant, and phrasing, the output only keeps the latest version.

Gemini macOS

Gemini macOS can read the currently selected screen content after user authorization, then combine it with voice commands to complete tasks. In the demo, it converts a photo of a whiteboard into a table, uses Nano Banana to generate a birthday image, and searches the web to fill in an event address.

OFFICIAL DEMO · BILINGUAL
Gemini macOS full demo. Transcription handles speech-to-text; whiteboard understanding, Nano Banana image generation, and web search are part of a larger product orchestration.

Download bilingual video

Here, speech-to-text is handled by Gemini 3.5 Transcribe, while screen understanding, web search, and image generation come from other models and tools within the Gemini app.

Antigravity

Antigravity combines voice commands with the code context in the editor. In the demo, the user asks it to modify a Flutter app's theme, then continues testing or kicks off a build.

OFFICIAL DEMO · BILINGUAL
Antigravity demo: transcription captures the voice, while code context, testing, and building sit in the agent's execution layer.

Download bilingual video

The transcription model is responsible for turning speech into text; reading code, planning steps, and executing builds are Antigravity's agent capabilities. The Gemini 3.5 Transcribe model itself doesn't support function calling.

Google AI Studio already offers hands-on access to both models. The Chrome integration is still marked as "coming soon." Companies like Deepgram, AssemblyAI, and Krisp appear on the early partner list; these are integrations mentioned in the release materials, not independent evaluations.

Currently in Public Preview: know these limitations upfront

Both models are currently in Public Preview. You can start testing and integrating them, but before moving to production, you'll want to validate performance with your own accents, noise conditions, specialized terms, and long recordings.

Here are the main limitations:

  • Live sessions are capped at 10 minutes each, with no speaker diarization or word-level timestamps.
  • The recorded version handles up to 1 hour of audio; enabling speaker diarization or word-level timestamps reduces that to 30 minutes.
  • Smart mode cannot be combined with speaker diarization or word-level timestamps.
  • Word-level timestamps may lower transcription quality.
  • The Chrome integration hasn't launched yet.

Based on typical token usage, Google estimates the Live version costs roughly $0.009 per minute and the recorded version about $0.005 per minute. That translates to around $0.54 and $0.30 for an hour of audio, respectively. Actual billing is calculated based on input and output tokens, and may also include storage, moderation, and additional model inference costs.

Choosing between them is straightforward:

  • For real-time captions, live streaming, phone assistants, and voice agents, go with the Live version.
  • For meetings, interviews, customer service recordings, and subtitle production, use the recorded version.
  • Turn on Smart mode when you want text ready to send.
  • For verbatim evidence, speaker labels, or timestamps, disable Smart and stick with verbatim.

Gemini 3.5 Transcribe is now available for testing through the Gemini API, Vertex AI, and Google AI Studio. Its main selling points come down to four things: real-time responses, high accuracy on recordings, automatic Smart cleanup, and support for multiple languages and custom vocabulary.

Source
Intelligent transcription with Gemini 3.5 TranscribeGoogle·2026-08-26·View primary source
Site note
This article covers Google's product announcements and official API limits; benchmark figures come from Google and were not independently reproduced. Pricing, limits, and preview status were verified against official documentation as of August 27, 2026.