Model comparison
Gemma 4 31B vs Grok 4 Fast (Reasoning)
Head-to-head evidence from 12 shared benchmark results across 6 categories. Overall scores shown here use the public BenchAlign v5 ranking lane.
Public leaderboard positions: Gemma 4 31B #43 (Supported); Grok 4 Fast (Reasoning) #76 (Supported). Intervals and evidence labels describe ranking uncertainty, not a guarantee for a specific workload.
Evidence parity. Gemma 4 31B and Grok 4 Fast (Reasoning) share 12 comparable benchmark results. 0 of 8 categories are comparable. 17 results are unique to Gemma 4 31B; 1 to Grok 4 Fast (Reasoning).
Updated July 23, 2026- Shared results
- 12
- Gemma 4 31B only
- 17
- Grok 4 Fast (Reasoning) only
- 1
- Comparable categories
- 0 / 8
Benchmark data for Gemma 4 31B and Grok 4 Fast (Reasoning) is coming soon on BenchLM.
Confidence note. This is a partial-evidence comparison with 12 shared benchmark results across 6 evidence categories; 0 of 8 categories currently have scoreable aggregates for both models. Treat the verdict as directional until coverage is more balanced.
Why this result
BenchLM has partial data for these models, but not enough overlapping benchmark coverage to produce a fair score-level comparison yet.
Grok 4 Fast (Reasoning) has the larger context window at 2M, compared with 256K for Gemma 4 31B.
Category breakdown
Exact category averages are shown below. Not measured means BenchLM does not have enough sourced public coverage for that model and category.
| Category | Gemma 4 31B | Δ | Grok 4 Fast (Reasoning) |
|---|---|---|---|
| Coding | Gemma 4 31B41.6 | MarginNo overlap | Grok 4 Fast (Reasoning)Not measured |
| Knowledge | Gemma 4 31B52.9 | MarginNo overlap | Grok 4 Fast (Reasoning)Not measured |
| Multimodal | Gemma 4 31B76.9 | MarginNo overlap | Grok 4 Fast (Reasoning)Not measured |
Operational comparison
Runtime and commercial metrics are compared only when both models have a complete sourced value.
| Metric | Gemma 4 31B | Grok 4 Fast (Reasoning) | Comparison |
|---|---|---|---|
| Input / output priceUSD per 1M tokens | Gemma 4 31B$0 input / $0 output | Grok 4 Fast (Reasoning)Not available | A complete price comparison is not available. |
| Generation speedtokens per second | Gemma 4 31BNot available | Grok 4 Fast (Reasoning)Not available | A complete speed comparison is not available. |
| First-answer latencyseconds to first token | Gemma 4 31BNot available | Grok 4 Fast (Reasoning)Not available | A complete latency comparison is not available. |
| Context windowmaximum listed tokens | Gemma 4 31B256K | Grok 4 Fast (Reasoning)2M | Grok 4 Fast (Reasoning) lists the larger context window. |
Benchmark Deep Dive
Agentic9 benchmarks
| Benchmark | Gemma 4 31B | Grok 4 Fast (Reasoning) | Result |
|---|---|---|---|
| AA Agentic IndexSource | 14.4% | — | Not comparable |
| τ²-bench resultsSource | 59.9% | 65.8% | Grok 4 Fast (Reasoning) leads |
| GDPval-AASource | 15.2% | — | Not comparable |
| GDPval-AASource | 804 | — | Not comparable |
| Gert LabsSource | 35.26% | — | Not comparable |
| AA EnterpriseOps-GymSource | 28.3% | — | Not comparable |
| AA ITBenchSource | 37.3% | — | Not comparable |
| AA Tau3 BankingSource | 15.1% | — | Not comparable |
| terminalBenchHardSource | 36.4% | — | Not comparable |
Coding5 benchmarks
Reasoning2 benchmarks
Knowledge11 benchmarks
| Benchmark | Gemma 4 31B | Grok 4 Fast (Reasoning) | Result |
|---|---|---|---|
| GPQASource | 84.3% | — | Not comparable |
| MMLU-ProSource | 85.2% | — | Not comparable |
| HLESource | 26.5% | — | Not comparable |
| HLE w/o toolsSource | 19.5% | — | Not comparable |
| Artificial Analysis Intelligence IndexSource | 29.4% | 27.4% | Gemma 4 31B leads |
| AA-GPQA DiamondSource | 85.7% | 84.7% | Gemma 4 31B leads |
| AA-HLESource | 22.7% | 17.0% | Gemma 4 31B leads |
| AA-Omniscience IndexSource | -45.4% | -28.4% | Grok 4 Fast (Reasoning) leads |
| AA-Omniscience AccuracySource | 19.9% | 22.6% | Grok 4 Fast (Reasoning) leads |
| AA-Omniscience Hallucination RateSource | 81.6% | 66.0% | Grok 4 Fast (Reasoning) leads |
| AA Openness IndexSource | 38.9% | — | Not comparable |
Multimodal2 benchmarks
Inst. Following1 benchmarks
| Benchmark | Gemma 4 31B | Grok 4 Fast (Reasoning) | Result |
|---|---|---|---|
| AA-IFBenchSource | 75.6% | 50.5% | Gemma 4 31B leads |
Frequently Asked Questions (3)
Can I compare Gemma 4 31B and Grok 4 Fast (Reasoning) on BenchLM yet?
Not fully yet. BenchLM is tracking both models, but the sourced benchmark breakdown for this comparison is still coming soon.
Why does this comparison show “coming soon”?
BenchLM only shows category winners and benchmark-level calls when we have sourced results that can be compared fairly. For these models, the public benchmark coverage is not complete enough yet.
What data is available for Gemma 4 31B and Grok 4 Fast (Reasoning) today?
Gemma 4 31B: $0.00 input / $0.00 output per 1M tokens Both model pages still include creator, context window, reasoning mode, and other metadata while benchmark coverage fills in.
Self-host vs API cost
Estimates at 50,000 req/day · 1000 tokens/req average.
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