Model comparison
Claude 3.5 Sonnet vs GPT-5.5
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: Claude 3.5 Sonnet #132 (Estimated); GPT-5.5 #9 (Estimated). Intervals and evidence labels describe ranking uncertainty, not a guarantee for a specific workload.
Evidence parity. Claude 3.5 Sonnet and GPT-5.5 share 3 comparable benchmark results. 3 of 8 categories are comparable. 1 result is unique to Claude 3.5 Sonnet; 54 to GPT-5.5.
Updated July 22, 2026- Shared results
- 3
- Claude 3.5 Sonnet only
- 1
- GPT-5.5 only
- 54
- Comparable categories
- 3 / 8
Pick GPT-5.5 if you want the stronger benchmark profile. Claude 3.5 Sonnet only becomes the better choice if knowledge is the priority or you want the cheaper token bill.
Confidence note. This is a partial-evidence comparison with 3 shared benchmark results across 2 evidence categories; 3 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 is clearly ahead on the BenchAlign aggregate, 73.51 to 47.74. The gap is large enough that you do not need to squint at the spreadsheet to see the difference.
GPT-5.5's sharpest advantage is in mathematics, where it averages 47.6 against 1.6. The single biggest benchmark swing on the page is FrontierMath v2 (Tiers 1-3), 2.069% to 51.700%. Claude 3.5 Sonnet does hit back in knowledge, so the answer changes if that is the part of the workload you care about most.
GPT-5.5 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 3.5 Sonnet. That is roughly 2.0x on output cost alone. GPT-5.5 is the reasoning model in the pair, while Claude 3.5 Sonnet 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-5.5 gives you the larger context window at 1M, compared with 200K for Claude 3.5 Sonnet.
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 3.5 Sonnet | Δ | GPT-5.5 |
|---|---|---|---|
| Math | Claude 3.5 Sonnet1.6 | Margin→ 46.0 | GPT-5.547.6 |
| Coding | Claude 3.5 Sonnet49.0 | Margin→ 9.6 | GPT-5.558.6 |
| Knowledge | Claude 3.5 Sonnet59.4 | Margin← 1.6 | GPT-5.557.8 |
| Agentic | Claude 3.5 SonnetNot measured | MarginNo overlap | GPT-5.581.6 |
| Reasoning | Claude 3.5 SonnetNot measured | MarginNo overlap | GPT-5.585.0 |
| Multimodal | Claude 3.5 SonnetNot measured | MarginNo overlap | GPT-5.570.4 |
Decisive benchmark drivers
The largest measured benchmark gaps in this matchup, with exact reported values.
More
- Source ↗
FrontierMath v2 (Tiers 1-3)
MathA 2.069%B 51.700%Winner: GPT-5.5Δ 49.6FrontierMath v2 (Tiers 1-3): Claude 3.5 Sonnet scored 2.069%; GPT-5.5 scored 51.700%. GPT-5.5 wins this benchmark. - Source ↗
FrontierMath v2 (Tier 4)
MathA 0.000%B 35.400%Winner: GPT-5.5Δ 35.4FrontierMath v2 (Tier 4): Claude 3.5 Sonnet scored 0.000%; GPT-5.5 scored 35.400%. GPT-5.5 wins this benchmark. - Source ↗
GPQA
KnowledgeA 59.4%B 93.6%Winner: GPT-5.5Δ 34.2GPQA: Claude 3.5 Sonnet scored 59.4%; GPT-5.5 scored 93.6%. GPT-5.5 wins this benchmark.
Operational comparison
Runtime and commercial metrics are compared only when both models have a complete sourced value.
| Metric | Claude 3.5 Sonnet | GPT-5.5 | Comparison |
|---|---|---|---|
| Input / output priceUSD per 1M tokens | Claude 3.5 Sonnet$3 input / $15 output | GPT-5.5$5 input / $30 output | Claude 3.5 Sonnet has the lower combined listed price. |
| Generation speedtokens per second | Claude 3.5 SonnetNot available | GPT-5.5Not available | A complete speed comparison is not available. |
| First-answer latencyseconds to first token | Claude 3.5 SonnetNot available | GPT-5.5Not available | A complete latency comparison is not available. |
| Context windowmaximum listed tokens | Claude 3.5 Sonnet200K | GPT-5.51M | GPT-5.5 lists the larger context window. |
Benchmark Deep Dive
Agentic24 benchmarks
| Benchmark | Claude 3.5 Sonnet | GPT-5.5 | Result |
|---|---|---|---|
| Terminal-Bench 2.0Source | — | 82% | Not comparable |
| CyberGymSource | — | 81.8% | Not comparable |
| BrowseCompSource | — | 84.4% | Not comparable |
| OSWorld-VerifiedSource | — | 78.7% | Not comparable |
| MCP AtlasSource | — | 75.3% | Not comparable |
| ToolathlonSource | — | 55.6% | Not comparable |
| τ²-bench resultsSource | — | 93.9% | Not comparable |
| AA Agentic IndexSource | — | 44.9% | Not comparable |
| APEX-Agents-AASource | — | 37.7% | Not comparable |
| GDPval-AASource | — | 49.5% | Not comparable |
| GDPval-AASource | — | 1490 | Not comparable |
| Gert LabsSource | — | 72.93% | Not comparable |
| ResearchClawBenchSource | — | 17.0% | Not comparable |
| OSWorld 2.0Source | — | 13.0% | Not comparable |
| JobBenchSource | — | 42.7% | Not comparable |
| ExploitGymSource | — | 13.4% | Not comparable |
| AA BriefcaseSource | — | 1154 | Not comparable |
| AA AutomationBenchSource | — | 42.1% | Not comparable |
| AA EnterpriseOps-GymSource | — | 46.6% | Not comparable |
| AA Harvey LABSource | — | 86.3% | Not comparable |
| AA ITBenchSource | — | 45.8% | Not comparable |
| AA Tau3 BankingSource | — | 31.3% | Not comparable |
| terminalBenchHardSource | — | 60.6% | Not comparable |
| aaTerminalBench21Source | — | 84.3% | Not comparable |
CodingGPT-5.5 wins10 benchmarks
| Benchmark | Claude 3.5 Sonnet | GPT-5.5 | Result |
|---|---|---|---|
| SWE-bench VerifiedSource | 49% | — | Not comparable |
| SWE-bench ProSource | — | 58.6% | Not comparable |
| Terminal-Bench 2.0Source | — | 82.0% | Not comparable |
| Vibe Code BenchSource | — | 69.85% | Not comparable |
| React Native EvalsSource | — | 84.7% | Not comparable |
| cursorBench31Source | — | 59.2% | Not comparable |
| cursorBench32Source | — | 58.4% | Not comparable |
| AA Coding IndexSource | — | 74.9% | Not comparable |
| AA-SciCodeSource | — | 56.1% | Not comparable |
| FrontierCode 1.1 MainSource | — | 43.0% | Not comparable |
Reasoning5 benchmarks
KnowledgeClaude 3.5 Sonnet wins10 benchmarks
| Benchmark | Claude 3.5 Sonnet | GPT-5.5 | Result |
|---|---|---|---|
| GPQASource | 59.4% | 93.6% | GPT-5.5 leads |
| GPQA-DSource | — | 93.6% | Not comparable |
| HLESource | — | 52.2% | Not comparable |
| HLE w/o toolsSource | — | 41.4% | Not comparable |
| Artificial Analysis Intelligence IndexSource | — | 54.8% | Not comparable |
| AA-GPQA DiamondSource | — | 93.5% | Not comparable |
| AA-HLESource | — | 44.3% | Not comparable |
| AA-Omniscience IndexSource | — | 20.1% | Not comparable |
| AA-Omniscience AccuracySource | — | 56.9% | Not comparable |
| AA-Omniscience Hallucination RateSource | — | 85.5% | Not comparable |
MathGPT-5.5 wins3 benchmarks
Multimodal5 benchmarks
Inst. Following1 benchmarks
| Benchmark | Claude 3.5 Sonnet | GPT-5.5 | Result |
|---|---|---|---|
| AA-IFBenchSource | — | 75.9% | Not comparable |
Frequently Asked Questions (4)
Which is better, Claude 3.5 Sonnet or GPT-5.5?
GPT-5.5 is ahead on BenchLM's BenchAlign leaderboard, 73.51 to 47.74. The biggest single separator in this matchup is FrontierMath v2 (Tiers 1-3), where the scores are 2.069% and 51.700%.
Which is better for knowledge tasks, Claude 3.5 Sonnet or GPT-5.5?
Claude 3.5 Sonnet has the edge for knowledge tasks in this comparison, averaging 59.4 versus 57.8. Inside this category, GPQA is the benchmark that creates the most daylight between them.
Which is better for coding, Claude 3.5 Sonnet or GPT-5.5?
GPT-5.5 has the edge for coding in this comparison, averaging 58.6 versus 49. Claude 3.5 Sonnet stays close enough that the answer can still flip depending on your workload.
Which is better for math, Claude 3.5 Sonnet or GPT-5.5?
GPT-5.5 has the edge for math in this comparison, averaging 47.6 versus 1.6. Inside this category, FrontierMath v2 (Tiers 1-3) is the benchmark that creates the most daylight between them.
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