Model comparison
GPT-4.1 nano vs GPT-5.5 Pro
Head-to-head evidence from 2 shared benchmark results across 2 categories. Overall scores shown here use the public BenchAlign v5 ranking lane.
Public leaderboard positions: GPT-4.1 nano #161 (Estimated); GPT-5.5 Pro #38 (Estimated). Intervals and evidence labels describe ranking uncertainty, not a guarantee for a specific workload.
Evidence parity. GPT-4.1 nano and GPT-5.5 Pro share 2 comparable benchmark results. 2 of 8 categories are comparable. 19 results are unique to GPT-4.1 nano; 5 to GPT-5.5 Pro.
Updated July 22, 2026- Shared results
- 2
- GPT-4.1 nano only
- 19
- GPT-5.5 Pro only
- 5
- Comparable categories
- 2 / 8
Pick GPT-5.5 Pro if you want the stronger benchmark profile. GPT-4.1 nano only becomes the better choice if you want the cheaper token bill or you would rather avoid the extra latency and token burn of a reasoning model.
Confidence note. This is a partial-evidence comparison with 2 shared benchmark results across 2 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 Pro is clearly ahead on the BenchAlign aggregate, 63.69 to 42.06. The gap is large enough that you do not need to squint at the spreadsheet to see the difference.
GPT-5.5 Pro's sharpest advantage is in mathematics, where it averages 48.1 against 1. The single biggest benchmark swing on the page is FrontierMath v2 (Tiers 1-3), 1.034% to 51.000%.
GPT-5.5 Pro is also the more expensive model on tokens at $30.00 input / $180.00 output per 1M tokens, versus $0.10 input / $0.40 output per 1M tokens for GPT-4.1 nano. That is roughly 450.0x on output cost alone. GPT-5.5 Pro is the reasoning model in the pair, while GPT-4.1 nano 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.
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-4.1 nano | Δ | GPT-5.5 Pro |
|---|---|---|---|
| Math | GPT-4.1 nano1.0 | Margin→ 47.1 | GPT-5.5 Pro48.1 |
| Knowledge | GPT-4.1 nano50.3 | Margin→ 6.9 | GPT-5.5 Pro57.2 |
| Agentic | GPT-4.1 nanoNot measured | MarginNo overlap | GPT-5.5 Pro90.1 |
| Inst. Following | GPT-4.1 nano83.2 | 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 (Tiers 1-3)
MathA 1.034%B 51.000%Winner: GPT-5.5 ProΔ 50FrontierMath v2 (Tiers 1-3): GPT-4.1 nano scored 1.034%; GPT-5.5 Pro scored 51.000%. 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 | GPT-4.1 nano | GPT-5.5 Pro | Comparison |
|---|---|---|---|
| Input / output priceUSD per 1M tokens | GPT-4.1 nano$0.1 input / $0.4 output | GPT-5.5 Pro$30 input / $180 output | GPT-4.1 nano has the lower combined listed price. |
| Generation speedtokens per second | GPT-4.1 nano181 tok/s | GPT-5.5 ProNot available | A complete speed comparison is not available. |
| First-answer latencyseconds to first token | GPT-4.1 nano0.63 s | GPT-5.5 ProNot available | A complete latency comparison is not available. |
| Context windowmaximum listed tokens | GPT-4.1 nano1M | GPT-5.5 Pro1M | Listed context windows are equal. |
Benchmark Deep Dive
Agentic5 benchmarks
Coding2 benchmarks
Reasoning2 benchmarks
KnowledgeGPT-5.5 Pro wins10 benchmarks
| Benchmark | GPT-4.1 nano | GPT-5.5 Pro | Result |
|---|---|---|---|
| MMLUSource | 80.1% | — | Not comparable |
| GPQASource | 50.3% | — | Not comparable |
| Artificial Analysis Intelligence IndexSource | 9.6% | — | Not comparable |
| AA-GPQA DiamondSource | 51.2% | — | Not comparable |
| AA-HLESource | 3.9% | — | Not comparable |
| AA-Omniscience IndexSource | -56.4% | — | Not comparable |
| AA-Omniscience AccuracySource | 13.3% | — | Not comparable |
| AA-Omniscience Hallucination RateSource | 80.4% | — | Not comparable |
| HLESource | — | 57.2% | Not comparable |
| HLE w/o toolsSource | — | 43.1% | Not comparable |
MathGPT-5.5 Pro wins3 benchmarks
Multimodal2 benchmarks
Frequently Asked Questions (3)
Which is better, GPT-4.1 nano or GPT-5.5 Pro?
GPT-5.5 Pro is ahead on BenchLM's BenchAlign leaderboard, 63.69 to 42.06. The biggest single separator in this matchup is FrontierMath v2 (Tiers 1-3), where the scores are 1.034% and 51.000%.
Which is better for knowledge tasks, GPT-4.1 nano or GPT-5.5 Pro?
GPT-5.5 Pro has the edge for knowledge tasks in this comparison, averaging 57.2 versus 50.3. GPT-4.1 nano stays close enough that the answer can still flip depending on your workload.
Which is better for math, GPT-4.1 nano or GPT-5.5 Pro?
GPT-5.5 Pro has the edge for math in this comparison, averaging 48.1 versus 1. Inside this category, FrontierMath v2 (Tiers 1-3) is the benchmark that creates the most daylight between them.
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