Model comparison
Claude Haiku 5.5 vs GPT-5.1
Claude Haiku 5.5 and GPT-5.1 score almost the same on the Noometry Index (49.5 vs 49.0), so choose on price, context window or the category you care about most.
Last verified . 5 shared benchmarks.
Summary
- They share 5 benchmarks with published results for both. Claude Haiku 5.5 scores higher in 3 categories and GPT-5.1 in 2 categories; 4 gaps are clear of the uncertainty.
- The widest gap is in math, where Claude Haiku 5.5 leads 73.6 to 52.2.
- The biggest single-benchmark swing is SimpleQA Verified: 23.8% for Claude Haiku 5.5 and 48% for GPT-5.1.
- Claude Haiku 5.5 is cheaper at $0.10 / $0.50 per million input/output tokens, against $1.25 / $10 for GPT-5.1.
- Claude Haiku 5.5 accepts more context: 1M tokens versus 400K.
Side by side
| Claude Haiku 5.5 | GPT-5.1 | |
|---|---|---|
| Provider | Anthropic | OpenAI |
| Noometry Index | 49.5 | 49.0 |
| Released | 2026-10-07 | 2025-11-13 |
| Weights | Proprietary | Proprietary |
| Context window | 1M | 400K |
| Max output | 128K | 128K |
| Input $ / M tokens | $0.10 | $1.25 |
| Output $ / M tokens | $0.50 | $10 |
| Results tracked | 9 | 63 |
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Category by category
Coding Claude Haiku 5.5 leads
Claude Haiku 5.5: 49.2 (#50), GPT-5.1: 46.4 (#66)
| Benchmark | Claude Haiku 5.5 | GPT-5.1 |
|---|---|---|
| LMArena WebDev | 1587 | 1395 |
| SWE-bench Verified | — | 68% |
| SWE-bench Verified (bash only) | — | 66% |
| SciCode | — | 43.3% |
| GSO | — | 13.7% |
| WeirdML | — | 60.8% |
| LiveBench Coding | — | 72.5% |
| LMArena Coding | — | 1454 |
| ALE-Bench | — | 1,192 |
Agentic & Tool Use Not comparable
Claude Haiku 5.5: —, GPT-5.1: 32.7 (#60)
| Benchmark | Claude Haiku 5.5 | GPT-5.1 |
|---|---|---|
| Terminal-Bench | — | 47.6% |
| DeepResearch Bench | — | 42.8% |
| LMArena Search | — | 1199 |
| Vending-Bench 2 | — | 1,473 |
Reasoning GPT-5.1 leads
Claude Haiku 5.5: 35.2 (#69), GPT-5.1: 39.8 (#58)
| Benchmark | Claude Haiku 5.5 | GPT-5.1 |
|---|---|---|
| Mystery Game Puzzles | 30% | 19% |
| ARC-AGI-2 | — | 17.6% |
| SimpleBench | — | 53.2% |
| NYT Connections (extended) | 65.7% | — |
| ARC-AGI-1 | — | 72.8% |
| CritPt | — | 4.9% |
| Chess Puzzles | — | 32% |
| EnigmaEval | — | 11.2% |
| LiveBench Reasoning | — | 95.8% |
| LMArena Hard Prompts | — | 1457 |
| DTBench | — | 90.1% |
| LiveBench Data Analysis | — | 72.1% |
| LMCA | — | 43.9% |
| Epoch Capabilities Index | — | 149.64 |
| ForecastBench | — | 58.1 |
| LiveBench | — | 78.8% |
Math Claude Haiku 5.5 leads
Claude Haiku 5.5: 73.6 (#18), GPT-5.1: 52.2 (#51)
| Benchmark | Claude Haiku 5.5 | GPT-5.1 |
|---|---|---|
| OTIS Mock AIME 2024-2025 | 98.9% | 88.6% |
| FrontierMath (Tiers 1-3) | 75.1% | — |
| FrontierMath Tier 4 | 46.3% | — |
| Omni-MATH | — | 46.4% |
| LiveBench Math | — | 94.5% |
| LMArena Math | — | 1447 |
| FrontierMath (Feb 2025 set) | — | 31% |
| FrontierMath Tier 4 (v1) | — | 12.5% |
Knowledge Too close to call
Claude Haiku 5.5: 50.8 (#70), GPT-5.1: 50.6 (#71)
| Benchmark | Claude Haiku 5.5 | GPT-5.1 |
|---|---|---|
| GPQA Diamond | 89.6% | 87.6% |
| SimpleQA Verified | 23.8% | 48% |
| Humanity's Last Exam | — | 23.7% |
| MMLU-Pro | — | 57.9% |
| Vectara Hallucination Rate | — | 10.9% |
| GPQA (HELM) | — | 44.2% |
| LMArena Expert | — | 1470 |
Multimodal GPT-5.1 leads
Claude Haiku 5.5: 43.7 (#21), GPT-5.1: 44.8 (#19)
| Benchmark | Claude Haiku 5.5 | GPT-5.1 |
|---|---|---|
| LMArena Vision | — | 1250 |
| VPCT | — | 58.7% |
| Furniture Assembly | 47.5% | — |
| LMArena Document | — | 1403 |
Multilingual Not comparable
Claude Haiku 5.5: —, GPT-5.1: 53.8 (#56)
| Benchmark | Claude Haiku 5.5 | GPT-5.1 |
|---|---|---|
| LMArena Non-English | — | 1431 |
| LMArena Chinese | — | 1495 |
| LMArena French | — | 1450 |
| LMArena German | — | 1438 |
| LMArena Japanese | — | 1453 |
| LMArena Korean | — | 1401 |
| LMArena Russian | — | 1435 |
| LMArena Spanish | — | 1433 |
Instruction Following Not comparable
Claude Haiku 5.5: —, GPT-5.1: 83.9 (#1)
| Benchmark | Claude Haiku 5.5 | GPT-5.1 |
|---|---|---|
| LiveBench Instruction Following | — | 93.3% |
| IFEval | — | 93.5% |
| LMArena Instruction Following | — | 1443 |
Long Context Not comparable
Claude Haiku 5.5: —, GPT-5.1: 47.6 (#14)
| Benchmark | Claude Haiku 5.5 | GPT-5.1 |
|---|---|---|
| CL-bench | — | 23.7% |
| CL-bench Life | — | 17.3% |
| LMArena Longer Query | — | 1447 |
Writing & Preference Not comparable
Claude Haiku 5.5: —, GPT-5.1: 64.5 (#55)
| Benchmark | Claude Haiku 5.5 | GPT-5.1 |
|---|---|---|
| LMArena Text | — | 1443 |
| LMArena Creative Writing | — | 1427 |
| WildBench | — | 86.3% |
| LMArena Multi-Turn | — | 1450 |
| LiveBench Language | — | 80.2% |
Frequently asked questions
Is Claude Haiku 5.5 better than GPT-5.1?
Claude Haiku 5.5 and GPT-5.1 score almost the same on the Noometry Index (49.5 vs 49.0), so choose on price, context window or the category you care about most.
Which is cheaper, Claude Haiku 5.5 or GPT-5.1?
Claude Haiku 5.5 is cheaper. It lists at $0.10 per million input tokens and $0.50 per million output tokens; GPT-5.1 lists at $1.25 and $10.
Is Claude Haiku 5.5 or GPT-5.1 better for coding?
Claude Haiku 5.5 scores higher on coding benchmarks: 49.2 versus 46.4 in the Noometry coding category.
Which has the bigger context window?
Claude Haiku 5.5 does, with 1M tokens against 400K.
How many benchmarks do Claude Haiku 5.5 and GPT-5.1 share?
5 benchmarks have published results for both models. Claude Haiku 5.5 has 9 scored results on Noometry and GPT-5.1 has 63.