Gemma 3 27B (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 #128); Gemma 4 31B is 1.3× cheaper per output token ($0.34/1M vs $0.45/1M); Gemma 4 31B offers the longer context window (262K vs 131K tokens); and Gemma 4 31B ships open weights.
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 27B vs Gemma 4 31B
Public benchmark boards where Gemma 3 27B or Gemma 4 31B has a published result
Gemma 4 31B ranks higher on the ModelCap Index as of 22 September 2026: #29 against #128. 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 27B cheaper than Gemma 4 31B?
Gemma 4 31B is cheaper on output tokens: $0.34/1M against $0.45/1M. Input tokens are $0.08/1M for Gemma 3 27B 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 $0.39 for Gemma 3 27B versus $0.35 for Gemma 4 31B. Gemma 4 31B costs 9.1% 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 27B or Gemma 4 31B?
Gemma 4 31B has the larger context window: 262K tokens against 131K.
Which is better for coding, Gemma 3 27B or Gemma 4 31B?
Are Gemma 3 27B and Gemma 4 31B open-weight models?
Gemma 3 27B: 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 27B and Gemma 4 31B?
ModelCap currently lists 4 API providers for Gemma 3 27B 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 27B 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.