Model comparison
Gemma 4 31B vs GPT-5.5 Pro
Head-to-head evidence from 3 shared benchmark results across 2 categories. Overall scores shown here use the public BenchAlign v5 ranking lane.
Public leaderboard positions: Gemma 4 31B #43 (Supported); GPT-5.5 Pro #38 (Estimated). Intervals and evidence labels describe ranking uncertainty, not a guarantee for a specific workload.
Evidence parity. Gemma 4 31B and GPT-5.5 Pro share 3 comparable benchmark results. 1 of 8 categories are comparable. 26 results are unique to Gemma 4 31B; 4 to GPT-5.5 Pro.
Updated July 22, 2026- Shared results
- 3
- Gemma 4 31B only
- 26
- GPT-5.5 Pro only
- 4
- Comparable categories
- 1 / 8
Pick GPT-5.5 Pro if you want the stronger benchmark profile. Gemma 4 31B only becomes the better choice if you want the cheaper token bill.
Confidence note. This is a partial-evidence comparison with 3 shared benchmark results across 2 evidence categories; 1 of 8 categories currently have scoreable aggregates for both models. Treat the verdict as directional until coverage is more balanced.
Why this result
GPT-5.5 Pro has the cleaner BenchAlign overall profile here, landing at 63.69 versus 61.08. It is a real lead, but still close enough that category-level strengths matter more than the headline number.
GPT-5.5 Pro's sharpest advantage is in knowledge, where it averages 57.2 against 52.9. The single biggest benchmark swing on the page is HLE, 26.5% to 57.2%.
GPT-5.5 Pro is also the more expensive model on tokens at $30.00 input / $180.00 output per 1M tokens, versus $0.00 input / $0.00 output per 1M tokens for Gemma 4 31B. That is roughly Infinityx on output cost alone. GPT-5.5 Pro gives you the larger context window at 1M, 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 | GPT-5.5 Pro |
|---|---|---|---|
| Knowledge | Gemma 4 31B52.9 | Margin→ 4.3 | GPT-5.5 Pro57.2 |
| Agentic | Gemma 4 31BNot measured | MarginNo overlap | GPT-5.5 Pro90.1 |
| Coding | Gemma 4 31B41.6 | MarginNo overlap | GPT-5.5 ProNot measured |
| Math | Gemma 4 31BNot measured | MarginNo overlap | GPT-5.5 Pro48.1 |
| Multimodal | Gemma 4 31B76.9 | MarginNo overlap | GPT-5.5 ProNot measured |
Decisive benchmark drivers
The largest measured benchmark gaps in this matchup, with exact reported values.
More
- Source ↗
HLE
KnowledgeA 26.5%B 57.2%Winner: GPT-5.5 ProΔ 30.7HLE: Gemma 4 31B scored 26.5%; GPT-5.5 Pro scored 57.2%. GPT-5.5 Pro wins this benchmark.
Operational comparison
Runtime and commercial metrics are compared only when both models have a complete sourced value.
| Metric | Gemma 4 31B | GPT-5.5 Pro | Comparison |
|---|---|---|---|
| Input / output priceUSD per 1M tokens | Gemma 4 31B$0 input / $0 output | GPT-5.5 Pro$30 input / $180 output | Gemma 4 31B has the lower combined listed price. |
| Generation speedtokens per second | Gemma 4 31BNot available | GPT-5.5 ProNot available | A complete speed comparison is not available. |
| First-answer latencyseconds to first token | Gemma 4 31BNot available | GPT-5.5 ProNot available | A complete latency comparison is not available. |
| Context windowmaximum listed tokens | Gemma 4 31B256K | GPT-5.5 Pro1M | GPT-5.5 Pro lists the larger context window. |
Benchmark Deep Dive
Agentic10 benchmarks
| Benchmark | Gemma 4 31B | GPT-5.5 Pro | Result |
|---|---|---|---|
| AA Agentic IndexSource | 14.4% | — | Not comparable |
| τ²-bench resultsSource | 59.9% | — | Not comparable |
| 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 |
| BrowseCompSource | — | 90.1% | Not comparable |
Coding4 benchmarks
Reasoning2 benchmarks
KnowledgeGPT-5.5 Pro wins11 benchmarks
| Benchmark | Gemma 4 31B | GPT-5.5 Pro | Result |
|---|---|---|---|
| GPQASource | 84.3% | — | Not comparable |
| MMLU-ProSource | 85.2% | — | Not comparable |
| HLESource | 26.5% | 57.2% | GPT-5.5 Pro leads |
| HLE w/o toolsSource | 19.5% | 43.1% | GPT-5.5 Pro leads |
| Artificial Analysis Intelligence IndexSource | 29.4% | — | Not comparable |
| AA-GPQA DiamondSource | 85.7% | — | Not comparable |
| AA-HLESource | 22.7% | — | Not comparable |
| AA-Omniscience IndexSource | -45.4% | — | Not comparable |
| AA-Omniscience AccuracySource | 19.9% | — | Not comparable |
| AA-Omniscience Hallucination RateSource | 81.6% | — | Not comparable |
| AA Openness IndexSource | 38.9% | — | Not comparable |
Math3 benchmarks
Multimodal2 benchmarks
Inst. Following1 benchmarks
| Benchmark | Gemma 4 31B | GPT-5.5 Pro | Result |
|---|---|---|---|
| AA-IFBenchSource | 75.6% | — | Not comparable |
Frequently Asked Questions (2)
Which is better, Gemma 4 31B or GPT-5.5 Pro?
GPT-5.5 Pro is ahead on BenchLM's BenchAlign leaderboard, 63.69 to 61.08. The biggest single separator in this matchup is HLE, where the scores are 26.5% and 57.2%.
Which is better for knowledge tasks, Gemma 4 31B or GPT-5.5 Pro?
GPT-5.5 Pro has the edge for knowledge tasks in this comparison, averaging 57.2 versus 52.9. Inside this category, HLE is the benchmark that creates the most daylight between them.
Self-host vs API cost
Estimates at 50,000 req/day · 1000 tokens/req average.
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