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Head-to-head comparison

Gemma 3 12B vs Gemma 4 31B

Gemma 3 12B (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 22 September 2026

As of 22 September 2026, Gemma 4 31B holds the stronger ModelCap Index position (#29 vs #161); Gemma 3 12B is 2.3× cheaper per output token ($0.15/1M vs $0.34/1M); Gemma 4 31B offers the longer context window (262K vs 131K tokens); and Gemma 4 31B ships open weights.

Which should you choose?

Choose Gemma 3 12B if…

  • API cost matters — $0.15/1M output tokens against $0.34/1M, about 2.3× cheaper.
  • your workload is prompt-heavy — input tokens cost $0.05/1M against $0.09/1M.

Choose Gemma 4 31B if…

  • you want the stronger overall ModelCap Index position — #29 against #161 (73.8 vs 36.0 points).
  • you need the longer context window — 262K tokens against 131K.
  • you want to self-host: Gemma 4 31B ships open weights while Gemma 3 12B is gated access.
  • you want provider choice — 11 listed API providers against 1.
  • Arena coding is your yardstick — 1499 against 1316.
  • you want the more recently listed model — Gemma 4 31B was listed 2 April 2026, Gemma 3 12B 13 March 2025.

Gemma 3 12B vs Gemma 4 31B: specs, pricing and context

Specification comparison of Gemma 3 12B and Gemma 4 31B
FieldGemma 3 12BGoogleGemma 4 31BGoogle
ModelCap Index position#161#29
Index score36.073.8
EvidenceMeasuredMeasured
Input price / 1M tokens$0.05$0.09
Output price / 1M tokens$0.15$0.34
Context window131K tokens262K tokens
Max output tokens16K16K
API providers listed111
Weight accessGated accessOpen weights
Input modalitiesText, ImageImage, Text, Video
First listed13 March 20252 April 2026
PublisherGoogleGoogle

Evidence: 2 public benchmark observations across 2 boards · 3 public benchmark observations across 3 boards. Prices are the lowest listed API offer per million tokens observed on the OpenRouter catalogue.

Benchmark scores: Gemma 3 12B vs Gemma 4 31B

Public benchmark boards where Gemma 3 12B or Gemma 4 31B has a published result
BoardGemma 3 12BGemma 4 31BLeads
Arena codingArena (LMArena)13161293–133914991483–1514Gemma 4 31B
BFCL V4UC Berkeley (Gorilla)30.4Prompt—Only one result
AA τ²-Bench TelecomArtificial Analysis—65.5%tau2:telecom:dual-control:pass-at-1:3-repeats:source-model="Gemma 4 31B (Non-reasoning)":reasoning=falseOnly one result
AA Humanity's Last ExamArtificial Analysis—11.8%hle:may-2025:text-only-2158:no-tools:pass-at-1:source-model="Gemma 4 31B (Non-reasoning)":reasoning=falseOnly 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.

Gemma 3 12B vs Gemma 4 31B: common questions

Is Gemma 3 12B better than Gemma 4 31B?

Gemma 4 31B ranks higher on the ModelCap Index as of 22 September 2026: #29 against #161. 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 Gemma 3 12B cheaper than Gemma 4 31B?

Gemma 3 12B is cheaper on output tokens: $0.15/1M against $0.34/1M. Input tokens are $0.05/1M for Gemma 3 12B and $0.09/1M 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 $0.17 for Gemma 3 12B versus $0.35 for Gemma 4 31B. Gemma 3 12B costs 50.0% 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, Gemma 3 12B or Gemma 4 31B?

Gemma 4 31B has the larger context window: 262K tokens against 131K.

Which is better for coding, Gemma 3 12B or Gemma 4 31B?

Arena coding: Gemma 3 12B 1316, Gemma 4 31B 1499 — Gemma 4 31B leads.

Are Gemma 3 12B and Gemma 4 31B open-weight models?

Gemma 3 12B: Gated access. Gemma 4 31B: Open weights. 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 Gemma 3 12B and Gemma 4 31B?

ModelCap currently lists 1 API provider for Gemma 3 12B and 11 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 Gemma 3 12B vs Gemma 4 31B comparison?

Every figure comes from the sealed ModelCap dataset published 22 September 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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