Gemini 3.1 Pro Preview vs Gemini 3.5 Flash
Gemini Pro capability against Gemini Flash speed inside one catalog.
What the numbers say
- Gemini 3.5 Flash is about 1.3x cheaper on output tokens (99.0 vs 132 credits per 1M).
- Both take the same 1.0M-token context window.
- Gemini 3.5 Flash is the newer release (May 2026 vs February 2026).
Derived from the live registry Zeplik routes and bills against. Credits: 1 credit = $0.10, raw provider rate with a 1.10x margin.
Side by side
Gemini 3.1 Pro Preview
Gemini 3.1 Pro Preview is Google’s frontier reasoning model, delivering enhanced software engineering performance, improved agentic reliability, and more efficient token usage across complex workflows. Building on the multimodal foundation...
- Provider
- Context window
- 1.0M tokens
- Input price
- 22.0 credits / 1M tokens ($2.00 raw)
- Output price
- 132 credits / 1M tokens ($12.00 raw)
- Vision (image input)
- Yes
- Tool calling
- Yes
- Extended reasoning
- No
Best for
- High-volume everyday tasks where speed and cost matter: summaries, drafts, quick questions
- Very long documents and codebases: a 1.0M-token window fits entire books or repositories in one conversation
- Working with images: screenshots, charts, photos and scanned documents alongside text
- Tool use and agents: reliably calls functions, so it can search, run skills and drive workflows
Gemini 3.5 Flash
Gemini 3.5 Flash is Google's high-efficiency multimodal model, bringing near-Pro level coding and reasoning at Flash-tier cost and speed. It is highly optimized for coding proficiency and parallel agentic execution...
- Provider
- Context window
- 1.0M tokens
- Input price
- 16.5 credits / 1M tokens ($1.50 raw)
- Output price
- 99.0 credits / 1M tokens ($9.00 raw)
- Vision (image input)
- Yes
- Tool calling
- Yes
- Extended reasoning
- No
Best for
- High-volume everyday tasks where speed and cost matter: summaries, drafts, quick questions
- Very long documents and codebases: a 1.0M-token window fits entire books or repositories in one conversation
- Working with images: screenshots, charts, photos and scanned documents alongside text
- Tool use and agents: reliably calls functions, so it can search, run skills and drive workflows
Try both on Zeplik
The honest answer to most model debates is to run your own prompt on both. Zeplik puts Gemini 3.1 Pro Preview and Gemini 3.5 Flash in the same chat, so you can switch mid-conversation and compare answers on the work you actually do.