Skip to content
ModelCap

Head-to-head comparison

Gemma 3 12B vs gpt-oss-20b

Gemma 3 12B (Google) and gpt-oss-20b (OpenAI) 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 9 September 2026

As of 9 September 2026, Gemma 3 12B holds the stronger ModelCap Index position (#133 vs #135); gpt-oss-20b is 1.2× cheaper per output token ($0.13/1M vs $0.15/1M); and gpt-oss-20b ships open weights.

Which should you choose?

Choose Gemma 3 12B if…

  • you want the stronger overall ModelCap Index position — #133 against #135 (30.0 vs 27.9 points).

Choose gpt-oss-20b if…

  • API cost matters — $0.13/1M output tokens against $0.15/1M, about 1.2× cheaper.
  • your workload is prompt-heavy — input tokens cost $0.03/1M against $0.05/1M.
  • you want to self-host: gpt-oss-20b ships open weights while Gemma 3 12B is gated access.
  • you want provider choice — 12 listed API providers against 1.
  • Arena coding is your yardstick — 1369 against 1316.
  • AA Intelligence Index is your yardstick — 9.0 against 3.8.
  • AA Terminal-Bench 2.1 is your yardstick — 13.9% against 0.0%.
  • AA τ²-Bench Telecom is your yardstick — 60.2% against 10.8%.
  • AA Humanity's Last Exam is your yardstick — 11.0% against 4.2%.
  • you want the more recently listed model — gpt-oss-20b was listed 5 August 2025, Gemma 3 12B 13 March 2025.

Gemma 3 12B vs gpt-oss-20b: specs, pricing and context

Specification comparison of Gemma 3 12B and gpt-oss-20b
FieldGemma 3 12BGooglegpt-oss-20bOpenAI
ModelCap Index position#133#135
Index score30.027.9
EvidenceMeasuredMeasured
Input price / 1M tokens$0.05$0.03
Output price / 1M tokens$0.15$0.13
Context window131K tokens131K tokens
Max output tokens16K118K
API providers listed112
Weight accessGated accessOpen weights
Input modalitiesText, ImageText
First listed13 March 20255 August 2025
PublisherGoogleOpenAI

Evidence: 3 public benchmark observations across 3 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 gpt-oss-20b

Public benchmark boards where Gemma 3 12B or gpt-oss-20b has a published result
BoardGemma 3 12Bgpt-oss-20bLeads
Arena codingArena (LMArena)13161293–134013691356–1382gpt-oss-20b
BFCL V4UC Berkeley (Gorilla)30.4Prompt—Only one result
AA Intelligence IndexArtificial Analysis3.8intelligence-index:v4.3:non-reasoning9.0intelligence-index:v4.3:highgpt-oss-20b
AA Terminal-Bench 2.1Artificial Analysis0.0%terminal-bench:2.1:terminus-2:e2b:pass-at-1:3-repeats:source-model="Gemma 3 12B":reasoning=false13.9%terminal-bench:2.1:terminus-2:e2b:pass-at-1:3-repeats:source-model="gpt-oss-20b (high)":reasoning=truegpt-oss-20b
AA τ²-Bench TelecomArtificial Analysis10.8%tau2:telecom:dual-control:pass-at-1:3-repeats:source-model="Gemma 3 12B":reasoning=false60.2%tau2:telecom:dual-control:pass-at-1:3-repeats:source-model="gpt-oss-20b (high)":reasoning=truegpt-oss-20b
AA Humanity's Last ExamArtificial Analysis4.2%hle:may-2025:text-only-2158:no-tools:pass-at-1:source-model="Gemma 3 12B":reasoning=false11.0%hle:may-2025:text-only-2158:no-tools:pass-at-1:source-model="gpt-oss-20b (high)":reasoning=truegpt-oss-20b

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 gpt-oss-20b: common questions

Is Gemma 3 12B better than gpt-oss-20b?

Gemma 3 12B ranks higher on the ModelCap Index as of 9 September 2026: #133 against #135. 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 overlap, so the rank difference alone does not establish a reliable capability advantage for your workload.

Is Gemma 3 12B cheaper than gpt-oss-20b?

gpt-oss-20b is cheaper on output tokens: $0.13/1M against $0.15/1M. Input tokens are $0.05/1M for Gemma 3 12B and $0.03/1M for gpt-oss-20b. 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 $0.13 for gpt-oss-20b. gpt-oss-20b costs 28.6% 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 gpt-oss-20b?

Both publish a 131K-token context window.

Which is better for coding, Gemma 3 12B or gpt-oss-20b?

Arena coding: Gemma 3 12B 1316, gpt-oss-20b 1369 — gpt-oss-20b leads. AA Terminal-Bench 2.1: Gemma 3 12B 0.0%, gpt-oss-20b 13.9% — gpt-oss-20b leads.

Are Gemma 3 12B and gpt-oss-20b open-weight models?

Gemma 3 12B: Gated access. gpt-oss-20b: 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 gpt-oss-20b?

ModelCap currently lists 1 API provider for Gemma 3 12B and 12 for gpt-oss-20b, 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 gpt-oss-20b comparison?

Every figure comes from the sealed ModelCap dataset published 9 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.

Explore further