LLM Reference

Gemini 3.1 Flash TTS Preview vs GPT-5.5

Gemini 3.1 Flash TTS Preview (2026) and GPT-5.5 (2026) are frontier reasoning models from Google DeepMind and OpenAI. Gemini 3.1 Flash TTS Preview ships a 16k-token context window, while GPT-5.5 ships a 1.05m-token context window. On pricing, Gemini 3.1 Flash TTS Preview costs $1/1M input tokens; GPT-5.5 ranges from $5 to $8/1M input tokens by tier. This comparison covers specs, pricing, API access, capabilities, benchmarks, input and output token costs, and production fit for coding and agent workloads.

GPT-5.5 fits 66x more tokens; pick it for long-context work and Gemini 3.1 Flash TTS Preview for tighter calls.

Decision scorecard

Local evidence first
SignalGemini 3.1 Flash TTS PreviewGPT-5.5
Best forgeneral production evaluationreasoning-heavy apps, multimodal apps, and tool-calling agents
Decision fitGeneralCoding, RAG, and Agents
Context window16k1.05m
Cheapest output-$30/1M tokens
Provider routes1 tracked4 tracked
Shared benchmarks0 shared0 shared

Decision tradeoffs

Choose Gemini 3.1 Flash TTS Preview when...
  • Use Gemini 3.1 Flash TTS Preview when your own prompt tests beat the comparison signals; the local data does not show a decisive standalone advantage yet.
Choose GPT-5.5 when...
  • GPT-5.5 has the larger context window for long prompts, retrieval packs, or transcript analysis.
  • GPT-5.5 has broader tracked provider coverage for fallback and route flexibility.
  • GPT-5.5 uniquely exposes Vision, Multimodal, and Reasoning in local model data.
  • Local decision data tags GPT-5.5 for Coding, RAG, and Agents.

Monthly cost at traffic

Estimate token spend from the cheapest tracked input and output route or tier on this page.

Gemini 3.1 Flash TTS Preview

Unavailable

Cheapest tracked route/tier: Google AI Studio

GPT-5.5

$11,500

Cheapest tracked route/tier: OpenAI API 0-272K input tokens

Cost delta unavailable until both models have sourced input and output token prices.

Switch friction

Gemini 3.1 Flash TTS Preview -> GPT-5.5
  • No overlapping tracked provider route is sourced for Gemini 3.1 Flash TTS Preview and GPT-5.5; plan for SDK, billing, or endpoint changes.
  • GPT-5.5 adds Vision, Multimodal, and Reasoning in local capability data.
GPT-5.5 -> Gemini 3.1 Flash TTS Preview
  • No overlapping tracked provider route is sourced for GPT-5.5 and Gemini 3.1 Flash TTS Preview; plan for SDK, billing, or endpoint changes.
  • Check replacement coverage for Vision, Multimodal, and Reasoning before moving production traffic.

Specs

Specification
Released2026-04-152026-04-23
Context window16k1.05m
Parameters
ArchitectureDecoder OnlyDecoder Only
LicenseProprietaryProprietary
OpennessProprietaryProprietary
WeightsNot releasedNot released
CodeUnknownUnknown
Commercial useCommercial use: conditionalCommercial use: conditional
Knowledge cutoff-2025-12

Pricing and availability

Pricing attributeGemini 3.1 Flash TTS PreviewGPT-5.5
Input price$1/1M tokens
0-272K input tokens
$5/1M tokens
Standard GPT-5.5 token pricing before the long-context surcharge threshold.
272K+ input tokens
$8/1M tokens
Long-context surcharge applies above 272K input tokens for the full session.
Output price-
0-272K input tokens
$30/1M tokens
Standard GPT-5.5 token pricing before the long-context surcharge threshold.
272K+ input tokens
$36/1M tokens
Long-context surcharge applies above 272K input tokens for the full session.
Providers

Capabilities

CapabilityGemini 3.1 Flash TTS PreviewGPT-5.5
VisionNoYes
MultimodalNoYes
ReasoningNoYes
JSON / Tool useNoYes
Structured outputsNoYes
Code executionNoYes
IDE integrationNoNo
Computer useNoNo
Parallel agentsNoNo

Benchmarks

No shared benchmark scores are currently available for this pair.

Continue comparing

Last reviewed: 2026-06-29. Data sourced from public model cards and provider documentation.