Model comparison
GPT-4.1 vs GPT-5.1
Head-to-head evidence from 16 shared benchmark results across 7 categories. Overall scores shown here use the public BenchAlign v5 ranking lane.
Public leaderboard positions: GPT-4.1 #111 (Supported); GPT-5.1 #101 (Estimated). Intervals and evidence labels describe ranking uncertainty, not a guarantee for a specific workload.
Evidence parity. GPT-4.1 and GPT-5.1 share 16 comparable benchmark results. 1 of 8 categories are comparable. 4 results are unique to GPT-4.1; 5 to GPT-5.1.
Updated July 24, 2026- Shared results
- 16
- GPT-4.1 only
- 4
- GPT-5.1 only
- 5
- Comparable categories
- 1 / 8
Pick GPT-5.1 if you want the stronger benchmark profile. GPT-4.1 only becomes the better choice if you want the cheaper token bill or you need the larger 1M context window.
Confidence note. This is a partial-evidence comparison with 16 shared benchmark results across 7 evidence categories; 1 of 8 categories currently have scoreable aggregates for both models. Treat the verdict as directional until coverage is more balanced.
Why this result
GPT-5.1 has the cleaner BenchAlign overall profile here, landing at 52.66 versus 50.44. It is a real lead, but still close enough that category-level strengths matter more than the headline number.
GPT-5.1's sharpest advantage is in mathematics, where it averages 26.4 against 4.1. The single biggest benchmark swing on the page is FrontierMath v2 (Tiers 1-3), 5.517% to 31.034%.
GPT-5.1 is also the more expensive model on tokens at $1.25 input / $10.00 output per 1M tokens, versus $2.00 input / $8.00 output per 1M tokens for GPT-4.1. GPT-5.1 is the reasoning model in the pair, while GPT-4.1 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-4.1 gives you the larger context window at 1M, compared with 200K for GPT-5.1.
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 | Δ | GPT-5.1 |
|---|---|---|---|
| Math | GPT-4.14.1 | Margin→ 22.3 | GPT-5.126.4 |
| Coding | GPT-4.154.6 | MarginNo overlap | GPT-5.1Not measured |
| Knowledge | GPT-4.166.3 | MarginNo overlap | GPT-5.1Not measured |
| Inst. Following | GPT-4.187.4 | MarginNo overlap | GPT-5.1Not measured |
Decisive benchmark drivers
The largest measured benchmark gaps in this matchup, with exact reported values.
More
- Source ↗
FrontierMath v2 (Tiers 1-3)
MathA 5.517%B 31.034%Winner: GPT-5.1Δ 25.5FrontierMath v2 (Tiers 1-3): GPT-4.1 scored 5.517%; GPT-5.1 scored 31.034%. GPT-5.1 wins this benchmark. - Source ↗
FrontierMath v2 (Tier 4)
MathA 0.000%B 12.500%Winner: GPT-5.1Δ 12.5FrontierMath v2 (Tier 4): GPT-4.1 scored 0.000%; GPT-5.1 scored 12.500%. GPT-5.1 wins this benchmark.
Operational comparison
Runtime and commercial metrics are compared only when both models have a complete sourced value.
| Metric | GPT-4.1 | GPT-5.1 | Comparison |
|---|---|---|---|
| Input / output priceUSD per 1M tokens | GPT-4.1$2 input / $8 output | GPT-5.1$1.25 input / $10 output | GPT-4.1 has the lower combined listed price. |
| Generation speedtokens per second | GPT-4.1108 tok/s | GPT-5.1111 tok/s | GPT-5.1 has the higher measured throughput. |
| First-answer latencyseconds to first token | GPT-4.11.02 s | GPT-5.157.47 s | GPT-4.1 reaches the first token sooner. |
| Context windowmaximum listed tokens | GPT-4.11M | GPT-5.1200K | GPT-4.1 lists the larger context window. |
Benchmark Deep Dive
Agentic5 benchmarks
Coding4 benchmarks
Reasoning2 benchmarks
Knowledge8 benchmarks
| Benchmark | GPT-4.1 | GPT-5.1 | Result |
|---|---|---|---|
| MMLUSource | 90.2% | — | Not comparable |
| GPQASource | 66.3% | — | Not comparable |
| Artificial Analysis Intelligence IndexSource | 19.4% | 36.9% | GPT-5.1 leads |
| AA-GPQA DiamondSource | 66.6% | 87.3% | GPT-5.1 leads |
| AA-HLESource | 4.6% | 26.5% | GPT-5.1 leads |
| AA-Omniscience IndexSource | -36.2% | 5.6% | GPT-5.1 leads |
| AA-Omniscience AccuracySource | 24.2% | 37.6% | GPT-5.1 leads |
| AA-Omniscience Hallucination RateSource | 79.6% | 51.3% | GPT-5.1 leads |
MathGPT-5.1 wins2 benchmarks
Multimodal2 benchmarks
Frequently Asked Questions (2)
Which is better, GPT-4.1 or GPT-5.1?
GPT-5.1 is ahead on BenchLM's BenchAlign leaderboard, 52.66 to 50.44. The biggest single separator in this matchup is FrontierMath v2 (Tiers 1-3), where the scores are 5.517% and 31.034%.
Which is better for math, GPT-4.1 or GPT-5.1?
GPT-5.1 has the edge for math in this comparison, averaging 26.4 versus 4.1. Inside this category, FrontierMath v2 (Tiers 1-3) is the benchmark that creates the most daylight between them.