Model comparison
GPT-4.5 vs GPT-5.3 Chat
GPT-5.3 Chat is the stronger model overall, scoring 42.8 to 37.2 on the Noometry Index.
Last verified . 17 shared benchmarks.
Summary
- They share 17 benchmarks with published results for both. GPT-4.5 scores higher in 2 categories and GPT-5.3 Chat in 6 categories; 6 gaps are clear of the uncertainty.
- The widest gap is in reasoning, where GPT-5.3 Chat leads 28.5 to 13.9.
Side by side
| GPT-4.5 | GPT-5.3 Chat | |
|---|---|---|
| Provider | OpenAI | OpenAI |
| Noometry Index | 37.2 | 42.8 |
| Released | 2025-02-27 | 2026-03-03 |
| Weights | Proprietary | Proprietary |
| Context window | — | 128K |
| Max output | — | 16K |
| Input $ / M tokens | — | $1.75 |
| Output $ / M tokens | — | $14 |
| Results tracked | 42 | 18 |
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Category by category
Coding Too close to call
GPT-4.5: 42.2 (#109), GPT-5.3 Chat: 41.4 (#124)
| Benchmark | GPT-4.5 | GPT-5.3 Chat |
|---|---|---|
| LMArena Coding | 1396 | 1408 |
| Aider Polyglot | 44.9% | — |
| WeirdML | 39.4% | — |
| LiveBench Coding | 75.2% | — |
Agentic & Tool Use Not comparable
GPT-4.5: 27.9 (#97), GPT-5.3 Chat: —
| Benchmark | GPT-4.5 | GPT-5.3 Chat |
|---|---|---|
| Cybench | 17.5% | — |
Reasoning GPT-5.3 Chat leads
GPT-4.5: 13.9 (#330), GPT-5.3 Chat: 28.5 (#102)
| Benchmark | GPT-4.5 | GPT-5.3 Chat |
|---|---|---|
| LMArena Hard Prompts | 1403 | 1399 |
| ARC-AGI-2 | 0.8% | — |
| SimpleBench | 34.5% | — |
| ARC-AGI-1 | 10.3% | — |
| EnigmaEval | 3.2% | — |
| LiveBench Reasoning | 71.1% | — |
| LiveBench Data Analysis | 64.3% | — |
| Epoch Capabilities Index | 136.74 | — |
| ForecastBench | 61.7 | — |
| LiveBench | 69% | — |
Math GPT-5.3 Chat leads
GPT-4.5: 32.6 (#211), GPT-5.3 Chat: 38.2 (#142)
| Benchmark | GPT-4.5 | GPT-5.3 Chat |
|---|---|---|
| LMArena Math | 1412 | 1389 |
| OTIS Mock AIME 2024-2025 | 37.8% | — |
| LiveBench Math | 69.3% | — |
| MATH Level 5 | 78.6% | — |
Knowledge GPT-5.3 Chat leads
GPT-4.5: 32.5 (#211), GPT-5.3 Chat: 38.8 (#140)
| Benchmark | GPT-4.5 | GPT-5.3 Chat |
|---|---|---|
| LMArena Expert | 1394 | 1397 |
| GPQA Diamond | 68.7% | — |
| Humanity's Last Exam | 5.4% | — |
| Confabulations | 13.6% | — |
Multimodal Not comparable
GPT-4.5: 37.6 (#71), GPT-5.3 Chat: —
| Benchmark | GPT-4.5 | GPT-5.3 Chat |
|---|---|---|
| LMArena Vision | 1195 | — |
| VPCT | 45% | — |
Multilingual GPT-4.5 leads
GPT-4.5: 52.5 (#83), GPT-5.3 Chat: 50.3 (#124)
| Benchmark | GPT-4.5 | GPT-5.3 Chat |
|---|---|---|
| LMArena Non-English | 1413 | 1382 |
| LMArena Chinese | 1421 | 1432 |
| LMArena French | 1418 | 1397 |
| LMArena German | 1457 | 1384 |
| LMArena Japanese | 1416 | 1352 |
| LMArena Korean | 1392 | 1346 |
| LMArena Russian | 1419 | 1400 |
| LMArena Spanish | — | 1371 |
Instruction Following Too close to call
GPT-4.5: 72.6 (#134), GPT-5.3 Chat: 72.8 (#129)
| Benchmark | GPT-4.5 | GPT-5.3 Chat |
|---|---|---|
| LMArena Instruction Following | 1404 | 1378 |
| LiveBench Instruction Following | 72.3% | — |
Long Context GPT-5.3 Chat leads
GPT-4.5: 40.4 (#155), GPT-5.3 Chat: 42.6 (#120)
| Benchmark | GPT-4.5 | GPT-5.3 Chat |
|---|---|---|
| LMArena Longer Query | 1406 | 1396 |
| Fiction.LiveBench | 63.9% | — |
Writing & Preference GPT-5.3 Chat leads
GPT-4.5: 56.9 (#134), GPT-5.3 Chat: 63.1 (#68)
| Benchmark | GPT-4.5 | GPT-5.3 Chat |
|---|---|---|
| LMArena Text | 1417 | 1389 |
| LMArena Creative Writing | 1394 | 1355 |
| EQ-Bench Creative Writing | 1258 | 1690 |
| LMArena Multi-Turn | 1444 | 1412 |
| Short-Story Creative Writing | 75.6% | — |
| LiveBench Language | 61.5% | — |
Frequently asked questions
Is GPT-4.5 better than GPT-5.3 Chat?
GPT-5.3 Chat is the stronger model overall, scoring 42.8 to 37.2 on the Noometry Index.
Is GPT-4.5 or GPT-5.3 Chat better for coding?
They score almost the same on coding (42.2 vs 41.4); test both on your own repository before choosing.
How many benchmarks do GPT-4.5 and GPT-5.3 Chat share?
17 benchmarks have published results for both models. GPT-4.5 has 42 scored results on Noometry and GPT-5.3 Chat has 18.