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Head-to-head comparison

Gemini 3.8 Flash vs Gemma 4 31B

Gemini 3.8 Flash (Google) and Gemma 4 31B (Google) 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 October 2026

As of 18 October 2026, Gemini 3.8 Flash holds the stronger ModelCap Index position (#5 vs #38); Gemma 4 31B is 10.3× cheaper per output token ($0.40/1M vs $4.13/1M); Gemini 3.8 Flash offers the longer context window (1M vs 262K tokens); and Gemma 4 31B ships open weights.

Which should you choose?

Choose Gemini 3.8 Flash if…

  • you want the stronger overall ModelCap Index position — #5 against #38 (83.5 vs 70.9 points).
  • you need the longer context window — 1M tokens against 262K.
  • Arena text is your yardstick — 1496 against 1452.
  • Arena coding is your yardstick — 1528 against 1502.
  • AA Terminal-Bench 2.1 is your yardstick — 87.6% against 29.2%.
  • AA Humanity's Last Exam is your yardstick — 47.8% against 11.8%.
  • you want the more recently listed model — Gemini 3.8 Flash was listed 2 September 2026, Gemma 4 31B 2 April 2026.

Choose Gemma 4 31B if…

  • API cost matters — $0.40/1M output tokens against $4.13/1M, about 10.3× cheaper.
  • your workload is prompt-heavy — input tokens cost $0.20/1M against $0.825/1M.
  • you want to self-host: Gemma 4 31B ships open weights while Gemini 3.8 Flash is no linked weights.
  • you want provider choice — 12 listed API providers against 2.

Gemini 3.8 Flash vs Gemma 4 31B: specs, pricing and context

Specification comparison of Gemini 3.8 Flash and Gemma 4 31B
FieldGemini 3.8 FlashGoogleGemma 4 31BGoogle
ModelCap Index position#5#38
Index score83.570.9
EvidenceMeasuredMeasured
Input price / 1M tokens$0.825$0.20
Output price / 1M tokens$4.13$0.40
Context window1M tokens262K tokens
Declared route output cap66K16K
API providers listed212
Weight accessNo linked weightsOpen weights
Input modalitiesText, Image, Video, File, AudioImage, Text, Video
First listed2 September 20262 April 2026
PublisherGoogleGoogle

Evidence: 5 public benchmark observations across 5 boards · 2 public benchmark observations across 2 boards. Prices are the lowest listed API offer per million tokens observed on the OpenRouter catalogue.

Benchmark scores: Gemini 3.8 Flash vs Gemma 4 31B

Public benchmark boards where Gemini 3.8 Flash or Gemma 4 31B has a published result
BoardGemini 3.8 FlashGemma 4 31BLeads
Arena textArena (LMArena)14961492–1501High14521445–1460Not reportedGemini 3.8 Flash
Arena codingArena (LMArena)15281521–1535High15021487–1517Gemini 3.8 Flash
LMArena AgentLMArena3.7%2.6%–4.8%High—Only one result
ARC-AGI-2ARC Prize Foundation89.2%High—Only one result
ARC-AGI-3ARC Prize Foundation10.4%High—Only one result
AA Intelligence IndexArtificial Analysis40.9High—Only one result
AA Terminal-Bench 2.1Artificial Analysis87.6%High29.2%Non-reasoningGemini 3.8 Flash
AA τ²-Bench TelecomArtificial Analysis—65.5%Non-reasoningOnly one result
AA Humanity's Last ExamArtificial Analysis47.8%High11.8%Non-reasoningGemini 3.8 Flash
Terminal-Bench 4.0Terminal-Bench (Laude Institute)19.1%15.7%–22.5%mini-SWE-agent · High—Only one result
WildClawBench OpenClawWildClawBench—37.6Only one result

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 3.8 Flash vs Gemma 4 31B: common questions

Is Gemini 3.8 Flash better than Gemma 4 31B?

Gemini 3.8 Flash ranks higher on the ModelCap Index as of 18 October 2026: #5 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. Their published uncertainty intervals do not overlap, but the aggregate Index does not predict performance on every task; compare the relevant benchmark configurations before choosing.

Is Gemini 3.8 Flash cheaper than Gemma 4 31B?

Gemma 4 31B is cheaper on output tokens: $0.40/1M against $4.13/1M. Input tokens are $0.825/1M for Gemini 3.8 Flash and $0.20/1M for Gemma 4 31B. Prices are the lowest listed API offer ModelCap observed, in USD per million tokens. For 1,000 requests with 2,000 input and 500 output tokens each (2M input + 0.5M output), the listed-rate estimate is $3.71 for Gemini 3.8 Flash versus $0.60 for Gemma 4 31B. Gemma 4 31B costs 83.8% less in this scenario. This excludes caching, batch discounts, prompt-length tiers, tool charges and retries; verify the selected endpoint before budgeting.

Which has the bigger context window, Gemini 3.8 Flash or Gemma 4 31B?

Gemini 3.8 Flash has the larger context window: 1M tokens against 262K. OpenRouter catalogue or provider-endpoint declaration. Limits can vary by provider and prompt length; a model-wide maximum has not been independently verified.

Which is better for coding, Gemini 3.8 Flash or Gemma 4 31B?

Arena coding: Gemini 3.8 Flash 1528, Gemma 4 31B 1502 — Gemini 3.8 Flash leads. AA Terminal-Bench 2.1: Gemini 3.8 Flash 87.6%, Gemma 4 31B 29.2% — Gemini 3.8 Flash leads.

Are Gemini 3.8 Flash and Gemma 4 31B open-weight models?

Gemini 3.8 Flash: No linked weights. Gemma 4 31B: Open weights. Open weights mean the checkpoint can be downloaded and self-hosted under its licence. A missing weight link does not identify every API or chat product that offers a model.

Where can I run Gemini 3.8 Flash and Gemma 4 31B?

ModelCap currently lists 2 API providers for Gemini 3.8 Flash and 12 for Gemma 4 31B, from the OpenRouter catalogue snapshot the site serves; each model page lists the providers and their prices.

How current is this Gemini 3.8 Flash vs Gemma 4 31B comparison?

Every figure and ModelCap Index position comes from the same published snapshot dated 18 October 2026. Publication and page updates happen separately; use the snapshot date shown on the page.

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