Google

Gemini 3.1 Flash TTS

Reviewed by the GetInfoUs research teamLast reviewed: October 2026Editorial policy
72
Intelligence Index

Next-gen low-latency neural speech generation supporting inline emotion tags and conversational interruptions.

Technical Specifications

Provider
Google
Category
flagship
Release Date
2026-04
Knowledge Cutoff
January 2026
Architecture
Ultra-low-latency expressive acoustic speech model
Parameters
Confidential
Context Window
8K tokens
Max Output
4K tokens
Cached Input Price
$0 / 1M tokens
Batch API Discount
20% off async batch
Consumer Subscription
$20 / month
Reasoning Mode
No (Standard)
Reasoning Effort Control
Fixed
Tool Calling
No
Structured Outputs
No
Open Weights
No (Proprietary Cloud)
Input Modalities
text
Output Modalities
audio
Official Documentation
Visit Official Docs ↗

Data Privacy, Licensing & Deployment Governance

API Data Training Policy
API payloads are excluded from model training by default
Model License & Commercial Rights
Proprietary Commercial API (Google Terms)
Deployment & Cloud Availability
Google AI Studio API, Google Cloud Vertex AI
Output Ownership
Full commercial ownership of generated outputs

Official Provider Release Intelligence, API Quotas & Agentic Specs

Compare Multi-Models Side-by-Side →
Official API Model ID (SDK String)
models/gemini-3-1-flash-tts
Supported SDK & API Protocol
Google Gemini API (generateContent) + OpenAI-Compatible SDK
Lifecycle & Deprecation Status
Active GA (Guaranteed support through 2028+)
Production Rate Limits (RPM & TPM)
10,000 – 30,000 RPM (Tier 5 Enterprise) · 800,000 – 2,000,000 TPM
Long-Context Pricing Tier (>128K / >200K)
Flat rate ($0.75/1M in) across full 8K window
Prompt Cache Write & TTL Policy
Implicit + Explicit Context Caching at $0/1M with configurable TTL
Computer Use & Browser GUI Agent
Text-only completion (No GUI action loop)
MCP & Parallel Tool Calling
Prompt-based JSON extraction only
Web Search Grounding & Code Sandbox
Built-in Google Search Grounding + Managed Python Code Execution Sandbox
Fine-Tuning & Distillation Support
Vertex AI Supervised Adapter Tuning & Context Distillation
Multimodal Tokenization Billing
Text BPE (~4 chars/token)
Weights Precision & Quantization
Cloud-Hosted Proprietary (FP8 / BF16 Tensor Core Cluster)
Minimum GPU VRAM Requirement
Zero Local VRAM Required (100% Serverless Cloud API)
Supported Inference Engines
Managed Google Cloud API
System Card & Safety Framework
Google DeepMind Frontier Safety Framework Verified
Enterprise Compliance (SOC2 / HIPAA / ZDR)
SOC2 Type II · GDPR · Zero Data Retention (ZDR) & HIPAA BAA Available on Enterprise Tier
Engineering & Pricing Workbench

Gemini 3.1 Flash TTS Cost, Context, Hardware & API Integration

500 / day
4,000 tok
1,000 tok
Conversation Depth (History Re-billing):1 Turn (Single-Shot)
50%
Estimated Monthly API Cost (30 Days)
$202.50$225.00
Monthly Savings: $22.50 (Caching/Batch)
Subscription ($20/mo) vs API

For single-user chat, a $20/mo subscription caps your bill below this API volume.

Break-even point: ~49 requests/day equals $20/month.

Same Monthly Workload Cost Across Popular Reference Models

Gemini 3.1 Flash TTS (Active)
$202.50
/ month
Gemini 2.5 Flash
$18.00
/ month
DeepSeek V3
$32.70
/ month
GPT-4o
$300.00
/ month
Claude 3.7 Sonnet
$405.00
/ month

Live Prompt Paste Tokenizer & Cost Counter

Paste real system instructions, JSON schemas, or code to measure BPE token counts across tokenizers.

Chars / Words
175 / 24
OpenAI o200k
~46 tok
Claude BPE
~49 tok
Llama / DeepSeek
~51 tok

Hybrid Prompt Routing Cascade Simulator

Route routine queries to a fast lightweight model ($0.15/1M) and escalate only complex reasoning turns to Gemini 3.1 Flash TTS:

Cascaded Monthly Bill:$64.13/mo
Saves $138.38/mo (68% cost reduction) vs sending 100% of traffic to Gemini 3.1 Flash TTS.

Benchmark Scores & 6-Axis Capability Radar

Benchmark Encyclopedia
Coding (72)Reasoning (72)Knowledge (72)Speed (80)Context (55)Cost Value (72)
Gemini 3.1 Flash TTS2026 Frontier Median
Chatbot Arena Elo
1360pts

Strengths

  • Sub-250ms time-to-first-audio chunk
  • Supports inline audio tags like [laughter] and [sigh]
  • Ultra-natural conversational cadence

Limitations & Trade-offs

  • Restricted 8K context window
  • Higher output pricing than text-only models

Editorial Assessment

State-of-the-art conversational voice synthesis for latency-critical agents.

Best for: Real-time voice bots, live telephonic agents, and gaming NPCs

Frequently Asked Questions about Gemini 3.1 Flash TTS

How much does the Gemini 3.1 Flash TTS API cost per 1M tokens?+

Gemini 3.1 Flash TTS by Google is priced at $0.75 per 1M input tokens and $12 per 1M output tokens. With prompt caching enabled, cached input tokens cost $0 per 1M tokens, and asynchronous Batch API requests receive a 20% discount.

Should I use a $20/month subscription or the Gemini 3.1 Flash TTS pay-as-you-go API?+

A flat $20/month consumer subscription is predictable for daily interactive chat and manual coding. However, if you are building software, running automated workflows, or sending low-to-moderate volume with prompt caching enabled, the pay-as-you-go API is typically far more cost-effective and offers higher rate limits without manual UI caps.

How many words and pages fit in Gemini 3.1 Flash TTS's context window?+

Gemini 3.1 Flash TTS features a 8K tokens context window, which equals approximately 6,144 English words or ~16 standard single-spaced pages in a single prompt. Its maximum output generation per turn is 4,096 tokens.

Can I run Gemini 3.1 Flash TTS locally on my own GPU (Open Weights)?+

No, Gemini 3.1 Flash TTS is a proprietary closed-weights model hosted by Google. It cannot be downloaded for local GPU execution and must be accessed via Google's official API or cloud platform.

Does Google train on data sent to the Gemini 3.1 Flash TTS API, and is commercial use allowed?+

API payloads are excluded from model training by default. License tier: Proprietary Commercial API (Google Terms). Full commercial ownership of generated outputs. Supported deployment channels include: Google AI Studio API, Google Cloud Vertex AI.

How does Gemini 3.1 Flash TTS perform on coding and reasoning benchmarks?+

Gemini 3.1 Flash TTS achieves a composite Intelligence Index of 72/100, scoring N/A% on SWE-bench Verified, N/A% on GPQA Diamond, N/A% on MMLU-Pro, and 1360 pts on Chatbot Arena Elo.

What is Gemini 3.1 Flash TTS best used for?+

Gemini 3.1 Flash TTS is best suited for: Real-time voice bots, live telephonic agents, and gaming NPCs. Assessment: State-of-the-art conversational voice synthesis for latency-critical agents.

Benchmark scores, token prices, and rate limits evolve rapidly as AI labs release model updates. Always verify current specifications and pricing on the official provider documentation.

Sources: Google DeepMind Audio Research & Vertex AI↗