Model comparison
GPT-5.5 vs o1
Head-to-head evidence from 14 shared benchmark results across 6 categories. Overall scores shown here use the public BenchAlign v5 ranking lane.
Public leaderboard positions: GPT-5.5 #9 (Estimated); o1 #129 (Estimated). Intervals and evidence labels describe ranking uncertainty, not a guarantee for a specific workload.
Evidence parity. GPT-5.5 and o1 share 14 comparable benchmark results. 2 of 8 categories are comparable. 43 results are unique to GPT-5.5; 2 to o1.
Updated July 22, 2026- Shared results
- 14
- GPT-5.5 only
- 43
- o1 only
- 2
- Comparable categories
- 2 / 8
Pick GPT-5.5 if you want the stronger benchmark profile. o1 only becomes the better choice if knowledge is the priority.
Confidence note. This is a partial-evidence comparison with 14 shared benchmark results across 6 evidence categories; 2 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 48.1. 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 9.3. The single biggest benchmark swing on the page is FrontierMath v2 (Tiers 1-3), 51.700% to 9.310%. o1 does hit back in knowledge, so the answer changes if that is the part of the workload you care about most.
o1 is also the more expensive model on tokens at $15.00 input / $60.00 output per 1M tokens, versus $5.00 input / $30.00 output per 1M tokens for GPT-5.5. That is roughly 2.0x on output cost alone. GPT-5.5 gives you the larger context window at 1M, compared with 200K for o1.
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-5.5 | Δ | o1 |
|---|---|---|---|
| Math | GPT-5.547.6 | Margin← 38.3 | o19.3 |
| Knowledge | GPT-5.557.8 | Margin→ 17.9 | o175.7 |
| Agentic | GPT-5.581.6 | MarginNo overlap | o1Not measured |
| Coding | GPT-5.558.6 | MarginNo overlap | o1Not measured |
| Reasoning | GPT-5.585.0 | MarginNo overlap | o1Not measured |
| Multimodal | GPT-5.570.4 | MarginNo overlap | o1Not measured |
| Inst. Following | GPT-5.5Not measured | MarginNo overlap | o192.2 |
Decisive benchmark drivers
The largest measured benchmark gaps in this matchup, with exact reported values.
More
- Source ↗
FrontierMath v2 (Tiers 1-3)
MathA 51.700%B 9.310%Winner: GPT-5.5Δ 42.4FrontierMath v2 (Tiers 1-3): GPT-5.5 scored 51.700%; o1 scored 9.310%. GPT-5.5 wins this benchmark. - Source ↗
GPQA
KnowledgeA 93.6%B 75.7%Winner: GPT-5.5Δ 17.9GPQA: GPT-5.5 scored 93.6%; o1 scored 75.7%. GPT-5.5 wins this benchmark.
Operational comparison
Runtime and commercial metrics are compared only when both models have a complete sourced value.
| Metric | GPT-5.5 | o1 | Comparison |
|---|---|---|---|
| Input / output priceUSD per 1M tokens | GPT-5.5$5 input / $30 output | o1$15 input / $60 output | GPT-5.5 has the lower combined listed price. |
| Generation speedtokens per second | GPT-5.5Not available | o198 tok/s | A complete speed comparison is not available. |
| First-answer latencyseconds to first token | GPT-5.5Not available | o132.29 s | A complete latency comparison is not available. |
| Context windowmaximum listed tokens | GPT-5.51M | o1200K | GPT-5.5 lists the larger context window. |
Benchmark Deep Dive
Agentic24 benchmarks
| Benchmark | GPT-5.5 | o1 | 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% | 62.6% | GPT-5.5 leads |
| 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 |
Coding9 benchmarks
| Benchmark | GPT-5.5 | o1 | Result |
|---|---|---|---|
| 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% | 39.7% | GPT-5.5 leads |
| AA-SciCodeSource | 56.1% | 35.8% | GPT-5.5 leads |
| FrontierCode 1.1 MainSource | 43.0% | — | Not comparable |
Reasoning5 benchmarks
Knowledgeo1 wins11 benchmarks
| Benchmark | GPT-5.5 | o1 | Result |
|---|---|---|---|
| GPQASource | 93.6% | 75.7% | 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% | 23.4% | GPT-5.5 leads |
| AA-GPQA DiamondSource | 93.5% | 74.7% | GPT-5.5 leads |
| AA-HLESource | 44.3% | 7.7% | GPT-5.5 leads |
| AA-Omniscience IndexSource | 20.1% | -10.5% | GPT-5.5 leads |
| AA-Omniscience AccuracySource | 56.9% | 34.7% | GPT-5.5 leads |
| AA-Omniscience Hallucination RateSource | 85.5% | 69.3% | o1 leads |
| MMLUSource | — | 91.8% | Not comparable |
MathGPT-5.5 wins3 benchmarks
Multimodal5 benchmarks
Frequently Asked Questions (3)
Which is better, GPT-5.5 or o1?
GPT-5.5 is ahead on BenchLM's BenchAlign leaderboard, 73.51 to 48.1. The biggest single separator in this matchup is FrontierMath v2 (Tiers 1-3), where the scores are 51.700% and 9.310%.
Which is better for knowledge tasks, GPT-5.5 or o1?
o1 has the edge for knowledge tasks in this comparison, averaging 75.7 versus 57.8. Inside this category, AA-HLE is the benchmark that creates the most daylight between them.
Which is better for math, GPT-5.5 or o1?
GPT-5.5 has the edge for math in this comparison, averaging 47.6 versus 9.3. Inside this category, FrontierMath v2 (Tiers 1-3) is the benchmark that creates the most daylight between them.
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