DapperGPTGo to App

GPT-6.1 Terra vs Gemini 3.8 Flash

How OpenAI's GPT-6.1 Terra and Google AI's Gemini 3.8 Flash differ on paper, from the specs each provider publishes.

Compare them on your promptBoth answer side by side, free with your own API keys.

Key differences

  • GPT-6.1 Terra accepts a larger context window: 1.05M tokens versus 1.05M for Gemini 3.8 Flash.
  • GPT-6.1 Terra can write longer replies, up to 128K output tokens against 66K.
  • GPT-6.1 Terra is the newer release (October 2026); Gemini 3.8 Flash came out in September 2026.
  • GPT-6.1 Terra lists extended thinking support that Gemini 3.8 Flash does not.

Side by side

SpecGPT-6.1 TerraGemini 3.8 Flash
ProviderOpenAIGoogle AI
ReleasedOctober 2026September 2026
Context window1.05M tokens1.05M tokens
Max output128K tokens66K tokens
Reasoning modelYesYes
Price per 1M tokens (in / out)See providerSee provider
CapabilitiesImage input, Reasoning, Coding, Tool calling, Structured output, Extended thinking, StreamingImage input, Reasoning, Coding, Tool calling, Structured output, Streaming

Specs as published by each provider. Benchmarks and output quality aren't covered here; the best test is your own prompts.

Specs only go so far. Ask both.

Send one message and get GPT-6.1 Terra and Gemini 3.8 Flash's answers side by side, with response time, tokens and cost for each. You'll need OpenAI and Google AI keys.

Open GPT-6.1 Terra vs Gemini 3.8 Flash

Other comparisons