Model comparison
Claude Sonnet 4.5 vs GPT-5.6 Sol
Head-to-head evidence from 4 shared benchmark results across 3 categories. Overall scores shown here use the public BenchAlign v5 ranking lane.
Public leaderboard positions: Claude Sonnet 4.5 #96 (Estimated); GPT-5.6 Sol #3 (Supported). Intervals and evidence labels describe ranking uncertainty, not a guarantee for a specific workload.
Evidence parity. Claude Sonnet 4.5 and GPT-5.6 Sol share 4 comparable benchmark results. 4 of 8 categories are comparable. 8 results are unique to Claude Sonnet 4.5; 42 to GPT-5.6 Sol.
Updated July 23, 2026- Shared results
- 4
- Claude Sonnet 4.5 only
- 8
- GPT-5.6 Sol only
- 42
- Comparable categories
- 4 / 8
Pick GPT-5.6 Sol if you want the stronger benchmark profile. Claude Sonnet 4.5 only becomes the better choice if coding is the priority or you want the cheaper token bill.
Confidence note. This is a partial-evidence comparison with 4 shared benchmark results across 3 evidence categories; 4 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 53.61. 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 11.2. The single biggest benchmark swing on the page is FrontierMath v2 (Tier 4), 4.167% to 83.000%. Claude Sonnet 4.5 does hit back in coding, so the answer changes if that is the part of the workload you care about most.
GPT-5.6 Sol is also the more expensive model on tokens at $5.00 input / $30.00 output per 1M tokens, versus $3.00 input / $15.00 output per 1M tokens for Claude Sonnet 4.5. That is roughly 2.0x on output cost alone. GPT-5.6 Sol is the reasoning model in the pair, while Claude Sonnet 4.5 is not. That usually helps on harder chain-of-thought-heavy tests, but it can also mean more latency and more token spend in real use. GPT-5.6 Sol gives you the larger context window at 1M, compared with 200K for Claude Sonnet 4.5.
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 | Claude Sonnet 4.5 | Δ | GPT-5.6 Sol |
|---|---|---|---|
| Math | Claude Sonnet 4.511.2 | Margin→ 76.3 | GPT-5.6 Sol87.5 |
| Agentic | Claude Sonnet 4.555.4 | Margin→ 36.6 | GPT-5.6 Sol92.0 |
| Coding | Claude Sonnet 4.577.2 | Margin← 12.6 | GPT-5.6 Sol64.6 |
| Knowledge | Claude Sonnet 4.583.4 | Margin→ 11.2 | GPT-5.6 Sol94.6 |
| Reasoning | Claude Sonnet 4.513.6 | MarginNo overlap | GPT-5.6 SolNot measured |
| Multimodal | Claude Sonnet 4.5Not 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 4.167%B 83.000%Winner: GPT-5.6 SolΔ 78.8FrontierMath v2 (Tier 4): Claude Sonnet 4.5 scored 4.167%; GPT-5.6 Sol scored 83.000%. GPT-5.6 Sol wins this benchmark. - Source ↗
FrontierMath v2 (Tiers 1-3)
MathA 13.495%B 89.000%Winner: GPT-5.6 SolΔ 75.5FrontierMath v2 (Tiers 1-3): Claude Sonnet 4.5 scored 13.495%; GPT-5.6 Sol scored 89.000%. GPT-5.6 Sol wins this benchmark. - Source ↗
Terminal-Bench 2.0
AgenticA 50%B 91.9%Winner: GPT-5.6 SolΔ 41.9Terminal-Bench 2.0: Claude Sonnet 4.5 scored 50%; GPT-5.6 Sol scored 91.9%. GPT-5.6 Sol wins this benchmark. - Source ↗
GPQA
KnowledgeA 83.4%B 94.6%Winner: GPT-5.6 SolΔ 11.2GPQA: Claude Sonnet 4.5 scored 83.4%; GPT-5.6 Sol scored 94.6%. 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 | Claude Sonnet 4.5 | GPT-5.6 Sol | Comparison |
|---|---|---|---|
| Input / output priceUSD per 1M tokens | Claude Sonnet 4.5$3 input / $15 output | GPT-5.6 Sol$5 input / $30 output | Claude Sonnet 4.5 has the lower combined listed price. |
| Generation speedtokens per second | Claude Sonnet 4.5Not available | GPT-5.6 SolNot available | A complete speed comparison is not available. |
| First-answer latencyseconds to first token | Claude Sonnet 4.5Not available | GPT-5.6 SolNot available | A complete latency comparison is not available. |
| Context windowmaximum listed tokens | Claude Sonnet 4.5200K | GPT-5.6 Sol1M | GPT-5.6 Sol lists the larger context window. |
Benchmark Deep Dive
AgenticGPT-5.6 Sol wins21 benchmarks
| Benchmark | Claude Sonnet 4.5 | GPT-5.6 Sol | Result |
|---|---|---|---|
| Terminal-Bench 2.0Source | 50% | 91.9% | GPT-5.6 Sol leads |
| OSWorld-VerifiedSource | 61.4% | — | Not comparable |
| VITA-BenchSource | 17.0% | — | Not comparable |
| Gert LabsSource | 48.51% | — | Not comparable |
| JobBenchSource | 27.7% | — | 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 Agentic IndexSource | — | 54.0% | Not comparable |
| τ²-bench resultsSource | — | 85.1% | Not comparable |
| GDPval-AASource | — | 61.8% | Not comparable |
| GDPval-AASource | — | 1736 | 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 |
CodingClaude Sonnet 4.5 wins9 benchmarks
| Benchmark | Claude Sonnet 4.5 | GPT-5.6 Sol | Result |
|---|---|---|---|
| SWE-bench VerifiedSource | 77.2% | — | Not comparable |
| 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 |
| AA Coding IndexSource | — | 77.4% | Not comparable |
| AA-SciCodeSource | — | 56.1% | Not comparable |
Reasoning5 benchmarks
KnowledgeGPT-5.6 Sol wins10 benchmarks
| Benchmark | Claude Sonnet 4.5 | GPT-5.6 Sol | Result |
|---|---|---|---|
| GPQASource | 83.4% | 94.6% | GPT-5.6 Sol leads |
| GPQA-DSource | — | 94.6% | Not comparable |
| HealthBench ProfessionalSource | — | 60.5% | Not comparable |
| HealthBench HardSource | — | 33.1% | Not comparable |
| Artificial Analysis Intelligence IndexSource | — | 58.9% | Not comparable |
| AA-GPQA DiamondSource | — | 94.1% | Not comparable |
| AA-HLESource | — | 47.2% | Not comparable |
| AA-Omniscience IndexSource | — | 21.7% | Not comparable |
| AA-Omniscience AccuracySource | — | 58.5% | Not comparable |
| AA-Omniscience Hallucination RateSource | — | 88.8% | Not comparable |
MathGPT-5.6 Sol wins4 benchmarks
Multimodal4 benchmarks
Inst. Following1 benchmarks
| Benchmark | Claude Sonnet 4.5 | GPT-5.6 Sol | Result |
|---|---|---|---|
| AA-IFBenchSource | — | 72.7% | Not comparable |
Frequently Asked Questions (5)
Which is better, Claude Sonnet 4.5 or GPT-5.6 Sol?
GPT-5.6 Sol is ahead on BenchLM's BenchAlign leaderboard, 81.96 to 53.61. The biggest single separator in this matchup is FrontierMath v2 (Tier 4), where the scores are 4.167% and 83.000%.
Which is better for knowledge tasks, Claude Sonnet 4.5 or GPT-5.6 Sol?
GPT-5.6 Sol has the edge for knowledge tasks in this comparison, averaging 94.6 versus 83.4. Inside this category, GPQA is the benchmark that creates the most daylight between them.
Which is better for coding, Claude Sonnet 4.5 or GPT-5.6 Sol?
Claude Sonnet 4.5 has the edge for coding in this comparison, averaging 77.2 versus 64.6. GPT-5.6 Sol stays close enough that the answer can still flip depending on your workload.
Which is better for math, Claude Sonnet 4.5 or GPT-5.6 Sol?
GPT-5.6 Sol has the edge for math in this comparison, averaging 87.5 versus 11.2. Inside this category, FrontierMath v2 (Tier 4) is the benchmark that creates the most daylight between them.
Which is better for agentic tasks, Claude Sonnet 4.5 or GPT-5.6 Sol?
GPT-5.6 Sol has the edge for agentic tasks in this comparison, averaging 92 versus 55.4. Inside this category, Terminal-Bench 2.0 is the benchmark that creates the most daylight between them.
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