Model comparison
Claude Sonnet 4.6 vs GPT-5.5 Pro
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 4.6 #32 (Supported); GPT-5.5 Pro #38 (Estimated). Intervals and evidence labels describe ranking uncertainty, not a guarantee for a specific workload.
Evidence parity. Claude Sonnet 4.6 and GPT-5.5 Pro share 4 comparable benchmark results. 3 of 8 categories are comparable. 29 results are unique to Claude Sonnet 4.6; 3 to GPT-5.5 Pro.
Updated July 22, 2026- Shared results
- 4
- Claude Sonnet 4.6 only
- 29
- GPT-5.5 Pro only
- 3
- Comparable categories
- 3 / 8
Pick Claude Sonnet 4.6 if you want the stronger benchmark profile. GPT-5.5 Pro only becomes the better choice if agentic is the priority or you need the larger 1M context window.
Confidence note. This is a partial-evidence comparison with 4 shared benchmark results across 3 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
Claude Sonnet 4.6 has the cleaner BenchAlign overall profile here, landing at 65.07 versus 63.69. It is a real lead, but still close enough that category-level strengths matter more than the headline number.
Claude Sonnet 4.6's sharpest advantage is in knowledge, where it averages 66 against 57.2. The single biggest benchmark swing on the page is FrontierMath v2 (Tier 4), 8.300% to 39.600%. GPT-5.5 Pro does hit back in agentic, so the answer changes if that is the part of the workload you care about most.
GPT-5.5 Pro is also the more expensive model on tokens at $30.00 input / $180.00 output per 1M tokens, versus $3.00 input / $15.00 output per 1M tokens for Claude Sonnet 4.6. That is roughly 12.0x on output cost alone. GPT-5.5 Pro is the reasoning model in the pair, while Claude Sonnet 4.6 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 Pro gives you the larger context window at 1M, compared with 200K for Claude Sonnet 4.6.
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 4.6 | Δ | GPT-5.5 Pro |
|---|---|---|---|
| Agentic | Claude Sonnet 4.665.2 | Margin→ 24.9 | GPT-5.5 Pro90.1 |
| Math | Claude Sonnet 4.626.4 | Margin→ 21.7 | GPT-5.5 Pro48.1 |
| Knowledge | Claude Sonnet 4.666.0 | Margin← 8.8 | GPT-5.5 Pro57.2 |
| Coding | Claude Sonnet 4.669.1 | MarginNo overlap | GPT-5.5 ProNot measured |
| Multimodal | Claude Sonnet 4.677.4 | MarginNo overlap | GPT-5.5 ProNot measured |
Decisive benchmark drivers
The largest measured benchmark gaps in this matchup, with exact reported values.
More
- Source ↗
FrontierMath v2 (Tier 4)
MathA 8.300%B 39.600%Winner: GPT-5.5 ProΔ 31.3FrontierMath v2 (Tier 4): Claude Sonnet 4.6 scored 8.300%; GPT-5.5 Pro scored 39.600%. GPT-5.5 Pro wins this benchmark. - Source ↗
FrontierMath v2 (Tiers 1-3)
MathA 32.400%B 51.000%Winner: GPT-5.5 ProΔ 18.6FrontierMath v2 (Tiers 1-3): Claude Sonnet 4.6 scored 32.400%; GPT-5.5 Pro scored 51.000%. GPT-5.5 Pro wins this benchmark. - Source ↗
HLE
KnowledgeA 49%B 57.2%Winner: GPT-5.5 ProΔ 8.2HLE: Claude Sonnet 4.6 scored 49%; 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 | Claude Sonnet 4.6 | GPT-5.5 Pro | Comparison |
|---|---|---|---|
| Input / output priceUSD per 1M tokens | Claude Sonnet 4.6$3 input / $15 output | GPT-5.5 Pro$30 input / $180 output | Claude Sonnet 4.6 has the lower combined listed price. |
| Generation speedtokens per second | Claude Sonnet 4.644 tok/s | GPT-5.5 ProNot available | A complete speed comparison is not available. |
| First-answer latencyseconds to first token | Claude Sonnet 4.61.48 s | GPT-5.5 ProNot available | A complete latency comparison is not available. |
| Context windowmaximum listed tokens | Claude Sonnet 4.6200K | GPT-5.5 Pro1M | GPT-5.5 Pro lists the larger context window. |
Benchmark Deep Dive
AgenticGPT-5.5 Pro wins9 benchmarks
| Benchmark | Claude Sonnet 4.6 | GPT-5.5 Pro | Result |
|---|---|---|---|
| Terminal-Bench 2.0Source | 59.1% | — | Not comparable |
| OSWorld-VerifiedSource | 72.1% | — | Not comparable |
| Claw-EvalSource | 67.8% | — | Not comparable |
| CyberGymSource | 65.2% | — | Not comparable |
| τ²-bench resultsSource | 79.5% | — | Not comparable |
| Gert LabsSource | 62.92% | — | Not comparable |
| OSWorld 2.0Source | 8.3% | — | Not comparable |
| JobBenchSource | 36.9% | — | Not comparable |
| BrowseCompSource | — | 90.1% | Not comparable |
Coding7 benchmarks
| Benchmark | Claude Sonnet 4.6 | GPT-5.5 Pro | Result |
|---|---|---|---|
| SWE-bench VerifiedSource | 79.6% | — | Not comparable |
| SWE-RebenchSource | 60.7% | — | Not comparable |
| React Native EvalsSource | 80.6% | — | Not comparable |
| Vibe Code BenchSource | 51.48% | — | Not comparable |
| cursorBench31Source | 48.8% | — | Not comparable |
| AA-SciCodeSource | 46.9% | — | Not comparable |
| FrontierCode 1.1 MainSource | 24.3% | — | Not comparable |
Reasoning2 benchmarks
KnowledgeClaude Sonnet 4.6 wins11 benchmarks
| Benchmark | Claude Sonnet 4.6 | GPT-5.5 Pro | Result |
|---|---|---|---|
| GPQASource | 89.9% | — | Not comparable |
| SuperGPQASource | 95% | — | Not comparable |
| MMLU-ProSource | 79.2% | — | Not comparable |
| HLESource | 49% | 57.2% | GPT-5.5 Pro leads |
| Artificial Analysis Intelligence IndexSource | 35.9% | — | Not comparable |
| AA-GPQA DiamondSource | 79.9% | — | Not comparable |
| AA-HLESource | 13.2% | — | Not comparable |
| AA-Omniscience IndexSource | -2.9% | — | Not comparable |
| AA-Omniscience AccuracySource | 38.0% | — | Not comparable |
| AA-Omniscience Hallucination RateSource | 65.9% | — | Not comparable |
| HLE w/o toolsSource | — | 43.1% | Not comparable |
MathGPT-5.5 Pro wins3 benchmarks
Multimodal3 benchmarks
Inst. Following1 benchmarks
| Benchmark | Claude Sonnet 4.6 | GPT-5.5 Pro | Result |
|---|---|---|---|
| AA-IFBenchSource | 41.2% | — | Not comparable |
Frequently Asked Questions (4)
Which is better, Claude Sonnet 4.6 or GPT-5.5 Pro?
Claude Sonnet 4.6 is ahead on BenchLM's BenchAlign leaderboard, 65.07 to 63.69. The biggest single separator in this matchup is FrontierMath v2 (Tier 4), where the scores are 8.300% and 39.600%.
Which is better for knowledge tasks, Claude Sonnet 4.6 or GPT-5.5 Pro?
Claude Sonnet 4.6 has the edge for knowledge tasks in this comparison, averaging 66 versus 57.2. Inside this category, HLE is the benchmark that creates the most daylight between them.
Which is better for math, Claude Sonnet 4.6 or GPT-5.5 Pro?
GPT-5.5 Pro has the edge for math in this comparison, averaging 48.1 versus 26.4. 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 4.6 or GPT-5.5 Pro?
GPT-5.5 Pro has the edge for agentic tasks in this comparison, averaging 90.1 versus 65.2. Claude Sonnet 4.6 stays close enough that the answer can still flip depending on your workload.
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