Model comparison

Gemini 3.1 Pro Preview vs Gemini 3.5 Flash

Compare Gemini 3.1 Pro Preview (Google) and Gemini 3.5 Flash (Google) by price, context, capabilities, and latency.

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Price deadline

Gemini Flash prices rise Jan 1, 2027

Per Google's published pricing page, Gemini Flash input prices double on Jan 1, 2027. The same workload runs an order of magnitude cheaper on DeepSeek and GLM. Source: Google pricing Full price breakdown

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Which should you pick?

  • Price: Gemini 3.5 Flash is cheaper ($1.50 / 1M tokens input / $9 / 1M tokens output) vs Gemini 3.1 Pro Preview ($2 / 1M tokens input / $12 / 1M tokens output).

Side by side

Gemini 3.1 Pro Preview vs Gemini 3.5 Flash — full comparison

Compare price, provider, context, capabilities, latency, and source basis.

ModelProviderInputOutputContextCapabilitiesBest forLatencyStatusSource
Gemini 3.1 Pro Previewgoogle/gemini-3.1-pro-previewGoogleStarting at $2 / 1M tokens$12 / 1M tokens1M
StreamingTool callingJSON modeVision
image understanding, multimodal chat2140-4141msCatalogPlatform curated
Gemini 3.5 Flashgoogle/gemini-3.5-flashGoogle$1.50 / 1M tokens$9 / 1M tokens1M
StreamingTool callingJSON modeVision
image understanding, multimodal chat0-0msCatalogPlatform curated

FAQ

Gemini 3.1 Pro Preview vs Gemini 3.5 Flash FAQ

Is Gemini 3.1 Pro Preview or Gemini 3.5 Flash cheaper?

Gemini 3.5 Flash is cheaper ($1.50 / 1M tokens input / $9 / 1M tokens output) vs Gemini 3.1 Pro Preview ($2 / 1M tokens input / $12 / 1M tokens output). Actual cost depends on your input/output token mix — estimate it with the pricing calculator.

Which has a larger context window, Gemini 3.1 Pro Preview or Gemini 3.5 Flash?

Both offer the same context window: 1M tokens.

Gemini 3.1 Pro Preview vs Gemini 3.5 Flash for Vision: which should I pick?

Both target Vision. Pick Gemini 3.5 Flash to optimize cost, or Gemini 3.1 Pro Preview for the longer context window. Test both on real prompts before committing production traffic.

Gemini 3.1 Pro Preview detailsGemini 3.5 Flash detailsPricing calculatorOpenAI-compatible quickstart