Model comparison
GPT-4.5 vs GPT-5.5
GPT-5.5 is the stronger model overall, scoring 63.4 to 37.2 on the Noometry Index.
Last verified . 26 shared benchmarks.
Summary
- They share 26 benchmarks with published results for both. GPT-4.5 scores higher in 0 categories and GPT-5.5 in 10 categories; 10 gaps are clear of the uncertainty.
- The widest gap is in reasoning, where GPT-5.5 leads 72.8 to 13.9.
- The biggest single-benchmark swing is ARC-AGI-1: 10.3% for GPT-4.5 and 95% for GPT-5.5.
Side by side
| GPT-4.5 | GPT-5.5 | |
|---|---|---|
| Provider | OpenAI | OpenAI |
| Noometry Index | 37.2 | 63.4 |
| Released | 2025-02-27 | 2026-04-23 |
| Weights | Proprietary | Proprietary |
| Context window | — | 1.05M |
| Max output | — | 128K |
| Input $ / M tokens | — | $5 |
| Output $ / M tokens | — | $30 |
| Results tracked | 42 | 71 |
Sponsored placements are available on pages like this one. Advertise on Noometry
Category by category
Coding GPT-5.5 leads
GPT-4.5: 42.2 (#109), GPT-5.5: 58.2 (#17)
| Benchmark | GPT-4.5 | GPT-5.5 |
|---|---|---|
| WeirdML | 39.4% | 84.9% |
| LMArena Coding | 1396 | 1494 |
| SWE-bench Verified | — | 80.6% |
| DeepSWE | — | 67% |
| FrontierCode | — | 43% |
| Aider Polyglot | 44.9% | — |
| LMArena WebDev | — | 1513 |
| SciCode | — | 56.1% |
| GSO | — | 40.2% |
| LiveBench Coding | 75.2% | — |
| MirrorCode | — | 10% |
| ALE-Bench | — | 1,943 |
Agentic & Tool Use GPT-5.5 leads
GPT-4.5: 27.9 (#97), GPT-5.5: 50.7 (#6)
| Benchmark | GPT-4.5 | GPT-5.5 |
|---|---|---|
| Terminal-Bench | — | 84.7% |
| APEX-Agents | — | 55.1% |
| OSWorld 2.0 | — | 13% |
| Remote Labor Index | — | 6.3% |
| τ²-bench Banking | — | 44.6% |
| Cybench | 17.5% | — |
| DeepResearch Bench | — | 54% |
| PostTrainBench | — | 27.2% |
| ExploitBench | — | 47.4% |
| GBAEval | — | 53.2% |
| GDP.pdf | — | 26% |
| LMArena Search | — | 1242 |
| Vending-Bench 2 | — | 7,524 |
Reasoning GPT-5.5 leads
GPT-4.5: 13.9 (#330), GPT-5.5: 72.8 (#11)
| Benchmark | GPT-4.5 | GPT-5.5 |
|---|---|---|
| ARC-AGI-2 | 0.8% | 85% |
| SimpleBench | 34.5% | 69% |
| ARC-AGI-1 | 10.3% | 95% |
| LMArena Hard Prompts | 1403 | 1489 |
| Epoch Capabilities Index | 136.74 | 159.1 |
| ForecastBench | 61.7 | 60.6 |
| Kagi LLM Benchmark | — | 88.8% |
| NYT Connections (extended) | — | 96.2% |
| CritPt | — | 27.1% |
| Chess Puzzles | — | 54% |
| EnigmaEval | 3.2% | — |
| EBR-Bench | — | 34.3% |
| LiveBench Reasoning | 71.1% | — |
| Mystery Game Puzzles | — | 56% |
| DTBench | — | 96% |
| LiveBench Data Analysis | 64.3% | — |
| LMCA | — | 54.3% |
| Surface Evolver Bench | — | 88.1% |
| Bench to the Future 3 | — | 0.14 |
| LiveBench | 69% | — |
Math GPT-5.5 leads
GPT-4.5: 32.6 (#211), GPT-5.5: 81.7 (#11)
| Benchmark | GPT-4.5 | GPT-5.5 |
|---|---|---|
| OTIS Mock AIME 2024-2025 | 37.8% | 100% |
| LMArena Math | 1412 | 1486 |
| FrontierMath (Tiers 1-3) | — | 85.3% |
| FrontierMath Tier 4 | — | 72.5% |
| MathArena Final-Answer Competitions | — | 94.3% |
| ProofBench | — | 50% |
| LiveBench Math | 69.3% | — |
| MATH Level 5 | 78.6% | — |
| FrontierMath (Feb 2025 set) | — | 51.7% |
| FrontierMath Erdős | — | 0% |
| FrontierMath Tier 4 (v1) | — | 35.4% |
Knowledge GPT-5.5 leads
GPT-4.5: 32.5 (#211), GPT-5.5: 64.4 (#17)
| Benchmark | GPT-4.5 | GPT-5.5 |
|---|---|---|
| GPQA Diamond | 68.7% | 94% |
| LMArena Expert | 1394 | 1508 |
| Humanity's Last Exam | 5.4% | — |
| SimpleQA Verified | — | 63% |
| Confabulations | 13.6% | — |
| Vectara Hallucination Rate | — | 9.3% |
Multimodal GPT-5.5 leads
GPT-4.5: 37.6 (#71), GPT-5.5: 46.9 (#12)
| Benchmark | GPT-4.5 | GPT-5.5 |
|---|---|---|
| LMArena Vision | 1195 | 1297 |
| VPCT | 45% | — |
| Blueprint-Bench 2 | — | 36.2% |
| Furniture Assembly | — | 44.2% |
| LMArena Document | — | 1486 |
Multilingual GPT-5.5 leads
GPT-4.5: 52.5 (#83), GPT-5.5: 56.4 (#20)
| Benchmark | GPT-4.5 | GPT-5.5 |
|---|---|---|
| LMArena Non-English | 1413 | 1467 |
| LMArena Chinese | 1421 | 1533 |
| LMArena French | 1418 | 1486 |
| LMArena German | 1457 | 1480 |
| LMArena Japanese | 1416 | 1498 |
| LMArena Korean | 1392 | 1460 |
| LMArena Russian | 1419 | 1473 |
| LMArena Spanish | — | 1468 |
Instruction Following GPT-5.5 leads
GPT-4.5: 72.6 (#134), GPT-5.5: 77.5 (#18)
| Benchmark | GPT-4.5 | GPT-5.5 |
|---|---|---|
| LMArena Instruction Following | 1404 | 1479 |
| LiveBench Instruction Following | 72.3% | — |
Long Context GPT-5.5 leads
GPT-4.5: 40.4 (#155), GPT-5.5: 48.3 (#12)
| Benchmark | GPT-4.5 | GPT-5.5 |
|---|---|---|
| LMArena Longer Query | 1406 | 1484 |
| Fiction.LiveBench | 63.9% | — |
| CL-bench Life | — | 22.2% |
Writing & Preference GPT-5.5 leads
GPT-4.5: 56.9 (#134), GPT-5.5: 72.7 (#13)
| Benchmark | GPT-4.5 | GPT-5.5 |
|---|---|---|
| LMArena Text | 1417 | 1472 |
| LMArena Creative Writing | 1394 | 1455 |
| EQ-Bench Creative Writing | 1258 | 1844 |
| LMArena Multi-Turn | 1444 | 1476 |
| Short-Story Creative Writing | 75.6% | — |
| EQ-Bench 4 | — | 1315 |
| LiveBench Language | 61.5% | — |
Frequently asked questions
Is GPT-4.5 better than GPT-5.5?
GPT-5.5 is the stronger model overall, scoring 63.4 to 37.2 on the Noometry Index.
Is GPT-4.5 or GPT-5.5 better for coding?
GPT-5.5 scores higher on coding benchmarks: 58.2 versus 42.2 in the Noometry coding category.
How many benchmarks do GPT-4.5 and GPT-5.5 share?
26 benchmarks have published results for both models. GPT-4.5 has 42 scored results on Noometry and GPT-5.5 has 71.