Model comparison
GPT-5.3 Chat vs GPT-5 Pro
GPT-5 Pro is the stronger model overall, scoring 46.2 to 42.1 on the Noometry Index. GPT-5.3 Chat costs 8.6× less per token, which makes it the better buy when GPT-5 Pro's lead doesn't matter for your workload.
Last verified . 0 shared benchmarks.
Summary
- The widest gap is in knowledge, where GPT-5 Pro leads 56.2 to 38.2.
- GPT-5.3 Chat is cheaper at $1.75 / $14 per million input/output tokens, against $15 / $120 for GPT-5 Pro.
- GPT-5 Pro accepts more context: 400K tokens versus 128K.
Side by side
| GPT-5.3 Chat | GPT-5 Pro | |
|---|---|---|
| Provider | OpenAI | OpenAI |
| Noometry Index | 42.1 | 46.2 |
| Released | 2026-03-03 | 2025-10-06 |
| Weights | Proprietary | Proprietary |
| Context window | 128K | 400K |
| Max output | 16K | 272K |
| Input $ / M tokens | $1.75 | $15 |
| Output $ / M tokens | $14 | $120 |
| Results tracked | 18 | 12 |
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Category by category
Coding GPT-5 Pro leads
GPT-5.3 Chat: 40.8 (#124), GPT-5 Pro: 43.4 (#77)
| Benchmark | GPT-5.3 Chat | GPT-5 Pro |
|---|---|---|
| WeirdML | — | 60.4% |
| LMArena Coding | 1408 | — |
| AlgoTune | — | 1.31 |
Reasoning GPT-5 Pro leads
GPT-5.3 Chat: 27.3 (#105), GPT-5 Pro: 39.2 (#52)
| Benchmark | GPT-5.3 Chat | GPT-5 Pro |
|---|---|---|
| ARC-AGI-2 | — | 18.3% |
| SimpleBench | — | 61.6% |
| Kagi LLM Benchmark | — | 76.8% |
| ARC-AGI-1 | — | 70.2% |
| EnigmaEval | — | 18.8% |
| LMArena Hard Prompts | 1399 | — |
| Epoch Capabilities Index | — | 150.26 |
Math GPT-5 Pro leads
GPT-5.3 Chat: 35.4 (#146), GPT-5 Pro: 48.0 (#53)
| Benchmark | GPT-5.3 Chat | GPT-5 Pro |
|---|---|---|
| FrontierMath (Tiers 1-3) | — | 55.8% |
| FrontierMath Tier 4 | — | 19.5% |
| LMArena Math | 1389 | — |
| FrontierMath Tier 4 (v1) | — | 14.6% |
Knowledge GPT-5 Pro leads
GPT-5.3 Chat: 38.2 (#137), GPT-5 Pro: 56.2 (#39)
| Benchmark | GPT-5.3 Chat | GPT-5 Pro |
|---|---|---|
| Humanity's Last Exam | — | 31.6% |
| LMArena Expert | 1397 | — |
Multilingual Not comparable
GPT-5.3 Chat: 50.5 (#119), GPT-5 Pro: —
| Benchmark | GPT-5.3 Chat | GPT-5 Pro |
|---|---|---|
| LMArena Non-English | 1383 | — |
| LMArena Chinese | 1433 | — |
| LMArena French | 1398 | — |
| LMArena German | 1384 | — |
| LMArena Japanese | 1351 | — |
| LMArena Korean | 1347 | — |
| LMArena Russian | 1400 | — |
| LMArena Spanish | 1371 | — |
Instruction Following Not comparable
GPT-5.3 Chat: 73.0 (#124), GPT-5 Pro: —
| Benchmark | GPT-5.3 Chat | GPT-5 Pro |
|---|---|---|
| LMArena Instruction Following | 1378 | — |
Long Context Not comparable
GPT-5.3 Chat: 42.6 (#115), GPT-5 Pro: —
| Benchmark | GPT-5.3 Chat | GPT-5 Pro |
|---|---|---|
| LMArena Longer Query | 1396 | — |
Writing & Preference Not comparable
GPT-5.3 Chat: 63.3 (#65), GPT-5 Pro: —
| Benchmark | GPT-5.3 Chat | GPT-5 Pro |
|---|---|---|
| LMArena Text | 1389 | — |
| LMArena Creative Writing | 1356 | — |
| EQ-Bench Creative Writing | 1690 | — |
| LMArena Multi-Turn | 1413 | — |
Frequently asked questions
Is GPT-5.3 Chat better than GPT-5 Pro?
GPT-5 Pro is the stronger model overall, scoring 46.2 to 42.1 on the Noometry Index. GPT-5.3 Chat costs 8.6× less per token, which makes it the better buy when GPT-5 Pro's lead doesn't matter for your workload.
Which is cheaper, GPT-5.3 Chat or GPT-5 Pro?
GPT-5.3 Chat is cheaper. It lists at $1.75 per million input tokens and $14 per million output tokens; GPT-5 Pro lists at $15 and $120.
Is GPT-5.3 Chat or GPT-5 Pro better for coding?
GPT-5 Pro scores higher on coding benchmarks: 43.4 versus 40.8 in the Noometry coding category.
Which has the bigger context window?
GPT-5 Pro does, with 400K tokens against 128K.
How many benchmarks do GPT-5.3 Chat and GPT-5 Pro share?
0 benchmarks have published results for both models. GPT-5.3 Chat has 18 scored results on Noometry and GPT-5 Pro has 12.