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Real-time translation technology guide

Real-Time Translation Technology: Models, Latency & How AnyDub Works

Learn how AI translation models translate speech in real time, why live translation has a delay, how speech-to-speech differs from traditional translation pipelines, and which technology is best for videos, meetings, and calls.

Updated July 23, 2026 · Technical overview · 12 min read

The short answer

AnyDub uses a low-latency speech-to-speech model for live translation.

In the current production architecture, AnyDub streams audio to Google's Gemini Live API using the Gemini Live Translate model family. The preferred model is gemini-3.5-live-translate-preview, with compatible server-side fallbacks. This is different from translating a completed recording: the system must interpret and respond while the speaker is still talking.

InputStreaming audio
OutputTranslated audio and transcripts
UseVideos, meetings and calls
GoalMeaning with natural delay

01 / Architecture

How real-time speech translation works

A production translator is a streaming pipeline. Audio is captured in small chunks, sent over a persistent connection, interpreted by a model, and returned as translated audio and text. Each stage overlaps with the next; the system does not wait for the entire video or meeting to finish.

1CaptureTab, microphone or local-video audio
2DecodeSpeech, language, timing and context
3TranslateMeaning, tone and target phrasing
4DeliverSubtitles, text or synthesized speech

A live system must make a good decision early, then stabilize it as more speech arrives. That is why streaming captions can revise themselves.

02 / AnyDub stack

Which models does AnyDub use?

AnyDub uses different model paths for different jobs. Live audio is optimized for conversation; text and video paths can prioritize context, structure or completeness.

LIVE AUDIO

Gemini Live Translate

gemini-3.5-live-translate-preview is preferred for low-latency speech-to-speech translation, streaming audio and input/output transcripts.

TEXT

Gemini text translation

Reader content, writing assistance and context-heavy translation can wait for a complete sentence or paragraph and prioritize terminology and formatting.

VIDEO

Gemini video understanding

Longer workflows can use a video-capable model to transcribe and translate timestamped speech when completeness matters more than live latency.

VOICE

Speech synthesis

Translated voice paths can use Google's speech-generation services and compatible Gemini TTS models. Voice, format and buffering affect perceived delay.

Why “preview”? Live translation models evolve quickly. Server-side routing lets AnyDub adopt a compatible model, add a fallback or tune the route without an extension update.

03 / Latency

Why is there a delay in translation?

There is no single translation delay. Experienced delay is the sum of several smaller waits:

Audio captureThe browser collects enough samples for a stable chunk.
Network round tripAudio travels to the model and the response travels back.
Speech recognitionThe system needs evidence to distinguish words, names and noise.
Context and turn detectionA phrase boundary can prevent a fragment being translated incorrectly.
GenerationThe model chooses a translation, voice style and timing.
Playback bufferA small buffer prevents gaps when packets arrive unevenly.

The core trade-off: lower latency means making decisions with less context. More context improves grammar, names and idioms, but waiting too long makes conversation unnatural.

04 / Model architectures

Direct speech-to-speech vs. cascaded translation

Neither architecture is universally better. They optimize for different needs.

DimensionDirect speech-to-speechCascaded pipeline
FlowAudio → translated audioAudio → speech-to-text → translation → text-to-speech
Best atNatural conversation and low interaction latencyControl, transcripts, terminology and replaceable components
Trade-offLess visibility into intermediate decisionsMore stages and accumulated latency
Use it forMeetings, calls and live videoArchives, captions and searchable transcripts

A hybrid is often practical: direct speech-to-speech for live playback, with transcripts and separate text or video models for deeper inspection.

05 / The market

What other translation models and platforms are available?

The market is not one leaderboard. Products combine speech recognition, machine translation, voice synthesis, streaming, customization and deployment differently.

Platform or approachArchitectureStrong fitMain consideration
Gemini Live TranslateDirect speech-to-speechLow-latency live audioPreview models and constraints can change
Azure AI SpeechSpeech translation with interim results and synthesisEnterprise speech and custom speechSupport varies by feature and region
Google Cloud Speech + Translation + TTSCascaded servicesModular applications with separate controlsLatency accumulates across services
DeepL APIText translation APIWritten translation and terminologyAudio still needs STT and TTS
Self-hosted open-source stacksComposable STT, translation and TTSPrivacy and custom deploymentOperations and quality tuning are yours

Official source citations

These live references point to the primary product documentation that supports the platform comparisons on this page.

05.1 / Competitive landscape

What makes each competitor different?

Every serious platform has a real strength. The meaningful question is not “which brand is best?” but “which system is best for this workflow?”

AZURE

Microsoft Azure AI Speech

Unique strength: enterprise speech tooling, custom speech, interim translation results, regional options, SDKs, and Microsoft ecosystem integration.

Best for: organizations building a controlled speech platform, call-center workflow, or custom vocabulary system.

Trade-off: teams generally assemble and operate more of the product pipeline themselves; support varies by feature, language, and region.

GOOGLE CLOUD

Google Cloud Speech, Translation & TTS

Unique strength: modular cloud services that let engineers choose separate speech recognition, text translation, and voice components.

Best for: products that need independent control over transcripts, translation APIs, voices, storage, and batch processing.

Trade-off: each network hop and processing stage can add latency and integration work.

DEEPL

DeepL

Unique strength: a text-first translation experience known for strong written-language quality and terminology-oriented workflows.

Best for: documents, websites, support content, business writing, and applications where the complete text is available before translation.

Trade-off: audio translation still requires separate speech recognition, streaming orchestration, and voice output.

OPEN SOURCE

Self-hosted speech stacks

Unique strength: maximum control over deployment, data boundaries, model selection, vocabulary, and customization.

Best for: research, regulated environments, private networks, and teams with ML infrastructure expertise.

Trade-off: the customer owns GPUs, scaling, monitoring, model upgrades, latency tuning, and quality maintenance.

05.2 / The AnyDub advantage

Why AnyDub is the strongest choice for live browser translation

AnyDub is not trying to be a generic translation API. It is a finished translation experience built around the moment a person is watching a video or speaking in a meeting.

1. One product, not four APIs

AnyDub connects audio capture, live translation, subtitles, translated voice, volume mixing, language selection, and playback into one browser workflow.

2. Designed for live use

The architecture is optimized for streaming audio and conversational delay, rather than waiting for an entire recording or paragraph to finish.

3. Works where the audio already is

The Chrome extension can translate YouTube, Netflix, Zoom, Google Meet, Teams, and other browser audio without asking users to export and upload a video first.

4. Multiple modes for different jobs

AnyDub can use live speech-to-speech for meetings, translated captions for video, text translation for reading, and video-aware processing for longer content.

5. Built for real listening

Users can combine the translated voice with the original voice, control the mix, and choose subtitles, dubbing, or both. The result is more useful than a raw translated sentence.

6. Model routing can evolve

Model selection stays server-side. AnyDub can adopt better compatible models and fallbacks without forcing users to reinstall the extension.

Our honest position: Azure is a stronger platform for some enterprise customization projects. DeepL can be a better fit for certain written documents. Self-hosted systems can be better when infrastructure control is the priority. But for a person who wants to open a browser video or live meeting and understand it in another language now, AnyDub combines the most important pieces in one purpose-built experience.

06 / Decision guide

Which model should you use for which need?

Live meetings

Use streaming speech-to-speech. Optimize for turn-taking, interruptions and stable playback.

Translated subtitles

Use streaming transcription plus translation when visible text and timestamp control matter.

Long videos

Use a video or batch pipeline when completeness, speakers and timeline alignment matter.

Documents

Use a text model or specialized translation API with terminology controls and review.

Privacy-sensitive work

Consider local or self-hosted models, or verify the provider's retention and regional-processing controls.

Lowest cost at scale

Measure audio, transcription, synthesis, retries, bandwidth and compute—not just tokens.

07 / Frequently asked questions

Real-time translation FAQ

Does a bigger model always translate better?

Not by itself. A live product also needs streaming support, fast first audio, stable turn handling, predictable cost and language coverage.

Why can a translation change after I hear the first words?

Streaming systems emit provisional results before a phrase is complete. More context can correct a word, name or sentence boundary.

Can translation have zero latency?

No, zero-latency translation is not realistic. Capture, computation, network transfer and playback all take time. The goal is low enough latency to remain useful and natural.

Does AnyDub translate from subtitles or audio?

AnyDub can translate directly from spoken audio for video and live streams, rather than requiring a pre-existing subtitle track.

Why does delay vary between languages?

Language structure changes timing. Speech rate, word order, morphology, voice availability and context needs can all change when the model can safely speak.

Is the model choice permanent?

No, model routing stays flexible. AnyDub keeps routing on the server so it can adopt newer compatible models or fallbacks without an extension update.

Install AnyDub and translate in real time.

Translate videos, meetings and live audio into 70+ languages with subtitles, translated voice or both.

Install AnyDub on Chrome