Model comparison
GPT-5.1 vs GPT-5.6 Sol
Head-to-head evidence from 18 shared benchmark results across 7 categories. Overall scores shown here use the public BenchAlign v5 ranking lane.
Public leaderboard positions: GPT-5.1 #94 (Estimated); GPT-5.6 Sol #3 (Supported). Intervals and evidence labels describe ranking uncertainty, not a guarantee for a specific workload.
Evidence parity. GPT-5.1 and GPT-5.6 Sol share 18 comparable benchmark results. 1 of 8 categories are comparable. 3 results are unique to GPT-5.1; 28 to GPT-5.6 Sol.
Updated July 23, 2026- Shared results
- 18
- GPT-5.1 only
- 3
- GPT-5.6 Sol only
- 28
- Comparable categories
- 1 / 8
Pick GPT-5.6 Sol if you want the stronger benchmark profile. GPT-5.1 only becomes the better choice if you want the cheaper token bill.
Confidence note. This is a partial-evidence comparison with 18 shared benchmark results across 7 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-5.6 Sol is clearly ahead on the BenchAlign aggregate, 81.96 to 53.65. The gap is large enough that you do not need to squint at the spreadsheet to see the difference.
GPT-5.6 Sol's sharpest advantage is in mathematics, where it averages 87.5 against 26.4. The single biggest benchmark swing on the page is FrontierMath v2 (Tier 4), 12.500% to 83.000%.
GPT-5.6 Sol is also the more expensive model on tokens at $5.00 input / $30.00 output per 1M tokens, versus $1.25 input / $10.00 output per 1M tokens for GPT-5.1. That is roughly 3.0x on output cost alone. GPT-5.6 Sol gives you the larger context window at 1M, compared with 200K for GPT-5.1.
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 | GPT-5.1 | Δ | GPT-5.6 Sol |
|---|---|---|---|
| Math | GPT-5.126.4 | Margin→ 61.1 | GPT-5.6 Sol87.5 |
| Agentic | GPT-5.1Not measured | MarginNo overlap | GPT-5.6 Sol92.0 |
| Coding | GPT-5.1Not measured | MarginNo overlap | GPT-5.6 Sol64.6 |
| Knowledge | GPT-5.1Not measured | MarginNo overlap | GPT-5.6 Sol94.6 |
| Multimodal | GPT-5.1Not measured | MarginNo overlap | GPT-5.6 Sol83.0 |
Decisive benchmark drivers
The largest measured benchmark gaps in this matchup, with exact reported values.
More
- Source ↗
FrontierMath v2 (Tier 4)
MathA 12.500%B 83.000%Winner: GPT-5.6 SolΔ 70.5FrontierMath v2 (Tier 4): GPT-5.1 scored 12.500%; GPT-5.6 Sol scored 83.000%. GPT-5.6 Sol wins this benchmark. - Source ↗
FrontierMath v2 (Tiers 1-3)
MathA 31.034%B 89.000%Winner: GPT-5.6 SolΔ 58FrontierMath v2 (Tiers 1-3): GPT-5.1 scored 31.034%; GPT-5.6 Sol scored 89.000%. GPT-5.6 Sol wins this benchmark.
Operational comparison
Runtime and commercial metrics are compared only when both models have a complete sourced value.
| Metric | GPT-5.1 | GPT-5.6 Sol | Comparison |
|---|---|---|---|
| Input / output priceUSD per 1M tokens | GPT-5.1$1.25 input / $10 output | GPT-5.6 Sol$5 input / $30 output | GPT-5.1 has the lower combined listed price. |
| Generation speedtokens per second | GPT-5.1111 tok/s | GPT-5.6 SolNot available | A complete speed comparison is not available. |
| First-answer latencyseconds to first token | GPT-5.157.47 s | GPT-5.6 SolNot available | A complete latency comparison is not available. |
| Context windowmaximum listed tokens | GPT-5.1200K | GPT-5.6 Sol1M | GPT-5.6 Sol lists the larger context window. |
Benchmark Deep Dive
Agentic18 benchmarks
| Benchmark | GPT-5.1 | GPT-5.6 Sol | Result |
|---|---|---|---|
| AA Agentic IndexSource | 21.0% | 54.0% | GPT-5.6 Sol leads |
| τ²-bench resultsSource | 81.9% | 85.1% | GPT-5.6 Sol leads |
| Gert LabsSource | 41.24% | — | Not comparable |
| GDPval-AASource | 24.4% | 61.8% | GPT-5.6 Sol leads |
| GDPval-AASource | 987 | 1736 | GPT-5.6 Sol leads |
| Terminal-Bench 2.0Source | — | 91.9% | Not comparable |
| BrowseCompSource | — | 92.2% | Not comparable |
| OSWorld 2.0Source | — | 62.6% | Not comparable |
| CyberGymSource | — | 84.5% | Not comparable |
| ExploitGymSource | — | 33.7% | Not comparable |
| ToolathlonSource | — | 58% | Not comparable |
| AA BriefcaseSource | — | 1501 | Not comparable |
| AA ITBenchSource | — | 56.2% | Not comparable |
| AA Tau3 BankingSource | — | 33.0% | Not comparable |
| AA AutomationBenchSource | — | 51.2% | Not comparable |
| AA Harvey LABSource | — | 87.2% | Not comparable |
| terminalBenchHardSource | — | 65.9% | Not comparable |
| aaTerminalBench21Source | — | 88% | Not comparable |
Coding9 benchmarks
| Benchmark | GPT-5.1 | GPT-5.6 Sol | Result |
|---|---|---|---|
| Vibe Code BenchSource | 24.61% | — | Not comparable |
| AA Coding IndexSource | 49.4% | 77.4% | GPT-5.6 Sol leads |
| AA-SciCodeSource | 43.3% | 56.1% | GPT-5.6 Sol leads |
| SWE-bench ProSource | — | 64.6% | Not comparable |
| Terminal-Bench 2.0Source | — | 91.9% | Not comparable |
| deepSweSource | — | 72.7% | Not comparable |
| FrontierCode 1.1 ExtendedSource | — | 60.6% | Not comparable |
| cursorBench32Source | — | 67.2% | Not comparable |
| VulcanBench v3Source | — | 87.0% | Not comparable |
Reasoning4 benchmarks
Knowledge10 benchmarks
| Benchmark | GPT-5.1 | GPT-5.6 Sol | Result |
|---|---|---|---|
| Artificial Analysis Intelligence IndexSource | 36.9% | 58.9% | GPT-5.6 Sol leads |
| AA-GPQA DiamondSource | 87.3% | 94.1% | GPT-5.6 Sol leads |
| AA-HLESource | 26.5% | 47.2% | GPT-5.6 Sol leads |
| AA-Omniscience IndexSource | 5.6% | 21.7% | GPT-5.6 Sol leads |
| AA-Omniscience AccuracySource | 37.6% | 58.5% | GPT-5.6 Sol leads |
| AA-Omniscience Hallucination RateSource | 51.3% | 88.8% | GPT-5.1 leads |
| GPQASource | — | 94.6% | Not comparable |
| GPQA-DSource | — | 94.6% | Not comparable |
| HealthBench ProfessionalSource | — | 60.5% | Not comparable |
| HealthBench HardSource | — | 33.1% | Not comparable |
MathGPT-5.6 Sol wins3 benchmarks
Multimodal4 benchmarks
Inst. Following1 benchmarks
| Benchmark | GPT-5.1 | GPT-5.6 Sol | Result |
|---|---|---|---|
| AA-IFBenchSource | 72.9% | 72.7% | GPT-5.1 leads |
Frequently Asked Questions (2)
Which is better, GPT-5.1 or GPT-5.6 Sol?
GPT-5.6 Sol is ahead on BenchLM's BenchAlign leaderboard, 81.96 to 53.65. The biggest single separator in this matchup is FrontierMath v2 (Tier 4), where the scores are 12.500% and 83.000%.
Which is better for math, GPT-5.1 or GPT-5.6 Sol?
GPT-5.6 Sol has the edge for math in this comparison, averaging 87.5 versus 26.4. Inside this category, FrontierMath v2 (Tier 4) is the benchmark that creates the most daylight between them.
Related Comparisons
Explore More
Choose a model with this week’s evidence
Join 2,000+ readers for ranking moves, pricing changes, and the claims that still need proof.
One email each week. Unsubscribe anytime.