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Head-to-head comparison

Gemini 3.1 Pro Preview vs Mistral Medium 3.5

Gemini 3.1 Pro Preview (Google) and Mistral Medium 3.5 (Mistral AI) compared on the ModelCap Index, API price, context window, provider availability, weight access and every public benchmark board they share. Figures are the same ones shown on the live rankings; nothing here is a hidden score.

Snapshot as of 18 August 2026

As of 18 August 2026, Gemini 3.1 Pro Preview holds the stronger ModelCap Index position (#7 vs #38); Mistral Medium 3.5 is 1.6× cheaper per output token ($7.50/1M vs $12.00/1M); and Gemini 3.1 Pro Preview offers the longer context window (1M vs 262K tokens).

Which should you choose?

Choose Gemini 3.1 Pro Preview if…

  • you want the stronger overall ModelCap Index position — #7 against #38 (78.1 vs 53.9 points).
  • you need the longer context window — 1M tokens against 262K.
  • you want provider choice — 2 listed API providers against 1.
  • Arena coding is your yardstick — 1521 against 1479.
  • LMArena Agent is your yardstick — -0.4% against -7.0%.
  • Artificial Analysis Intelligence Index is your yardstick — 47.7 against 30.4.

Choose Mistral Medium 3.5 if…

  • API cost matters — $7.50/1M output tokens against $12.00/1M, about 1.6× cheaper.
  • your workload is prompt-heavy — input tokens cost $1.50/1M against $2.00/1M.
  • you want the more recently listed model — Mistral Medium 3.5 was listed 30 April 2026, Gemini 3.1 Pro Preview 19 February 2026.

Gemini 3.1 Pro Preview vs Mistral Medium 3.5: specs, pricing and context

Specification comparison of Gemini 3.1 Pro Preview and Mistral Medium 3.5
FieldGemini 3.1 Pro PreviewGoogleMistral Medium 3.5Mistral AI
ModelCap Index position#7#38
Index score78.153.9
EvidenceMeasuredMeasured
Input price / 1M tokens$2.00$1.50
Output price / 1M tokens$12.00$7.50
Context window1M tokens262K tokens
Max output tokens66K—
API providers listed21
Weight accessAPI onlyAPI only
Input modalitiesAudio, File, Image, Text, VideoText, Image, File
First listed19 February 202630 April 2026
PublisherGoogleMistral AI

Evidence: 4 public benchmark observations across 4 boards · 4 public benchmark observations across 4 boards. Prices are the lowest listed API offer per million tokens observed on the OpenRouter catalogue.

Benchmark scores: Gemini 3.1 Pro Preview vs Mistral Medium 3.5

Public benchmark boards where Gemini 3.1 Pro Preview or Mistral Medium 3.5 has a published result
BoardGemini 3.1 Pro PreviewMistral Medium 3.5Leads
Arena codingArena (LMArena)15211516–152614791468–1490Gemini 3.1 Pro Preview
LMArena AgentLMArena-0.4%-1.2%–0.3%-7.0%-9.0%–-5.0%Gemini 3.1 Pro Preview
Artificial Analysis Intelligence IndexArtificial Analysis47.7intelligence-index30.4intelligence-indexGemini 3.1 Pro Preview

Scores are the sources' own published figures for each model's best evaluated configuration; ModelCap never re-runs a benchmark.

Want a different pairing? Open the interactive comparison tool to swap either model for any current ranked language model.

Gemini 3.1 Pro Preview vs Mistral Medium 3.5: common questions

Is Gemini 3.1 Pro Preview better than Mistral Medium 3.5?

Gemini 3.1 Pro Preview ranks higher on the ModelCap Index as of 18 August 2026: #7 against #38. That is a capability ranking built from public benchmark evidence with published uncertainty; whether it is "better" for you also depends on price, context and where you can run it.

Is Gemini 3.1 Pro Preview cheaper than Mistral Medium 3.5?

Mistral Medium 3.5 is cheaper on output tokens: $7.50/1M against $12.00/1M. Input tokens are $2.00/1M for Gemini 3.1 Pro Preview and $1.50/1M for Mistral Medium 3.5. Prices are the lowest listed API offer ModelCap observed, in USD per million tokens.

Which has the bigger context window, Gemini 3.1 Pro Preview or Mistral Medium 3.5?

Gemini 3.1 Pro Preview has the larger context window: 1M tokens against 262K.

Which is better for coding, Gemini 3.1 Pro Preview or Mistral Medium 3.5?

Arena coding: Gemini 3.1 Pro Preview 1521, Mistral Medium 3.5 1479 — Gemini 3.1 Pro Preview leads.

Are Gemini 3.1 Pro Preview and Mistral Medium 3.5 open-weight models?

Gemini 3.1 Pro Preview: API only. Mistral Medium 3.5: API only. Open weights mean the checkpoint can be downloaded and self-hosted under its licence; API-only models are available solely through hosted endpoints.

Where can I run Gemini 3.1 Pro Preview and Mistral Medium 3.5?

ModelCap currently lists 2 API providers for Gemini 3.1 Pro Preview and 1 for Mistral Medium 3.5, from the OpenRouter catalogue snapshot the site serves; each model page lists the providers and their prices.

How current is this Gemini 3.1 Pro Preview vs Mistral Medium 3.5 comparison?

Every figure comes from the sealed ModelCap dataset published 18 August 2026; the page re-renders within a minute of each data refresh, and the ModelCap Index positions are the same ones shown on the live rankings.

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