Model comparison
Gemini 2.5 Pro vs GPT-5.3 Chat
Gemini 2.5 Pro is the stronger model overall, scoring 45.0 to 42.8 on the Noometry Index.
Last verified . 18 shared benchmarks.
GoogleSummary
- They share 18 benchmarks with published results for both. Gemini 2.5 Pro scores higher in 7 categories and GPT-5.3 Chat in 1 category; 5 gaps are clear of the uncertainty.
- The widest gap is in long context, where Gemini 2.5 Pro leads 59.8 to 42.6.
- Gemini 2.5 Pro is cheaper at $1.25 / $10 per million input/output tokens, against $1.75 / $14 for GPT-5.3 Chat.
- Gemini 2.5 Pro accepts more context: 1.05M tokens versus 128K.
Side by side
| Gemini 2.5 Pro | GPT-5.3 Chat | |
|---|---|---|
| Provider | OpenAI | |
| Noometry Index | 45.0 | 42.8 |
| Released | 2025-03-25 | 2026-03-03 |
| Weights | Proprietary | Proprietary |
| Context window | 1.05M | 128K |
| Max output | 66K | 16K |
| Input $ / M tokens | $1.25 | $1.75 |
| Output $ / M tokens | $10 | $14 |
| Results tracked | 78 | 18 |
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Category by category
Coding Too close to call
Gemini 2.5 Pro: 42.4 (#101), GPT-5.3 Chat: 41.4 (#124)
| Benchmark | Gemini 2.5 Pro | GPT-5.3 Chat |
|---|---|---|
| LMArena Coding | 1452 | 1408 |
| SWE-bench Verified | 57.6% | — |
| SWE-bench Verified (bash only) | 53.6% | — |
| Aider Polyglot | 83.1% | — |
| LMArena WebDev | 1227 | — |
| SciCode | 42.8% | — |
| GSO | 3.9% | — |
| WeirdML | 54% | — |
| LiveBench Coding | 85.9% | — |
| CadEval | 64% | — |
| ALE-Bench | 785.52 | — |
| AlgoTune | 1.51 | — |
Agentic & Tool Use Not comparable
Gemini 2.5 Pro: 29.2 (#88), GPT-5.3 Chat: —
| Benchmark | Gemini 2.5 Pro | GPT-5.3 Chat |
|---|---|---|
| Terminal-Bench | 32.6% | — |
| GDPval | 23.3% | — |
| Remote Labor Index | 0.8% | — |
| TheAgentCompany | 30.3% | — |
| τ²-bench Banking | 13.7% | — |
| DeepResearch Bench | 42.8% | — |
| BALROG | 43.3% | — |
| LMArena Search | 1142 | — |
| METR Time Horizons | 55.4% | — |
| Vending-Bench 2 | 573.64 | — |
Reasoning Too close to call
Gemini 2.5 Pro: 28.8 (#99), GPT-5.3 Chat: 28.5 (#102)
| Benchmark | Gemini 2.5 Pro | GPT-5.3 Chat |
|---|---|---|
| LMArena Hard Prompts | 1455 | 1399 |
| ARC-AGI-2 | 4.9% | — |
| SimpleBench | 62.4% | — |
| Kagi LLM Benchmark | 70.3% | — |
| ARC-AGI-1 | 41% | — |
| CritPt | 2% | — |
| Chess Puzzles | 20% | — |
| EnigmaEval | 5.6% | — |
| LiveBench Reasoning | 89.8% | — |
| DTBench | 82.4% | — |
| LiveBench Data Analysis | 79.9% | — |
| LMCA | 34.8% | — |
| Epoch Capabilities Index | 145.32 | — |
| ForecastBench | 61.3 | — |
| LiveBench | 82.3% | — |
Math GPT-5.3 Chat leads
Gemini 2.5 Pro: 32.5 (#213), GPT-5.3 Chat: 38.2 (#142)
| Benchmark | Gemini 2.5 Pro | GPT-5.3 Chat |
|---|---|---|
| LMArena Math | 1450 | 1389 |
| FrontierMath (Tiers 1-3) | 24.6% | — |
| FrontierMath Tier 4 | 0% | — |
| OTIS Mock AIME 2024-2025 | 84.7% | — |
| Omni-MATH | 41.6% | — |
| LiveBench Math | 90.2% | — |
| MATH Level 5 | 95.9% | — |
| FrontierMath (Feb 2025 set) | 14.1% | — |
| FrontierMath Tier 4 (v1) | 4.2% | — |
Knowledge Gemini 2.5 Pro leads
Gemini 2.5 Pro: 56.0 (#46), GPT-5.3 Chat: 38.8 (#140)
| Benchmark | Gemini 2.5 Pro | GPT-5.3 Chat |
|---|---|---|
| LMArena Expert | 1452 | 1397 |
| GPQA Diamond | 85.3% | — |
| Humanity's Last Exam | 21.6% | — |
| MMLU-Pro | 86.3% | — |
| Confabulations | 10.6% | — |
| Vectara Hallucination Rate | 7% | — |
| GPQA (HELM) | 74.9% | — |
Multimodal Not comparable
Gemini 2.5 Pro: 45.2 (#18), GPT-5.3 Chat: —
| Benchmark | Gemini 2.5 Pro | GPT-5.3 Chat |
|---|---|---|
| LMArena Vision | 1263 | — |
| GeoBench | 86% | — |
| VPCT | 48% | — |
| LMArena Document | 1421 | — |
| SpatialViz-Bench | 44.7% | — |
Multilingual Gemini 2.5 Pro leads
Gemini 2.5 Pro: 55.3 (#31), GPT-5.3 Chat: 50.3 (#124)
| Benchmark | Gemini 2.5 Pro | GPT-5.3 Chat |
|---|---|---|
| LMArena Non-English | 1451 | 1382 |
| LMArena Chinese | 1507 | 1432 |
| LMArena French | 1472 | 1397 |
| LMArena German | 1487 | 1384 |
| LMArena Japanese | 1461 | 1352 |
| LMArena Korean | 1434 | 1346 |
| LMArena Russian | 1461 | 1400 |
| LMArena Spanish | 1473 | 1371 |
Instruction Following Gemini 2.5 Pro leads
Gemini 2.5 Pro: 75.0 (#75), GPT-5.3 Chat: 72.8 (#129)
| Benchmark | Gemini 2.5 Pro | GPT-5.3 Chat |
|---|---|---|
| LMArena Instruction Following | 1437 | 1378 |
| LiveBench Instruction Following | 80.6% | — |
| IFEval | 84% | — |
Long Context Gemini 2.5 Pro leads
Gemini 2.5 Pro: 59.8 (#5), GPT-5.3 Chat: 42.6 (#120)
| Benchmark | Gemini 2.5 Pro | GPT-5.3 Chat |
|---|---|---|
| LMArena Longer Query | 1449 | 1396 |
| Fiction.LiveBench | 91.7% | — |
Writing & Preference Too close to call
Gemini 2.5 Pro: 63.7 (#62), GPT-5.3 Chat: 63.1 (#68)
| Benchmark | Gemini 2.5 Pro | GPT-5.3 Chat |
|---|---|---|
| LMArena Text | 1458 | 1389 |
| LMArena Creative Writing | 1454 | 1355 |
| EQ-Bench Creative Writing | 1421 | 1690 |
| LMArena Multi-Turn | 1453 | 1412 |
| Short-Story Creative Writing | 83.8% | — |
| WildBench | 85.7% | — |
| LiveBench Language | 67.8% | — |
Frequently asked questions
Is Gemini 2.5 Pro better than GPT-5.3 Chat?
Gemini 2.5 Pro is the stronger model overall, scoring 45.0 to 42.8 on the Noometry Index.
Which is cheaper, Gemini 2.5 Pro or GPT-5.3 Chat?
Gemini 2.5 Pro is cheaper. It lists at $1.25 per million input tokens and $10 per million output tokens; GPT-5.3 Chat lists at $1.75 and $14.
Is Gemini 2.5 Pro or GPT-5.3 Chat better for coding?
They score almost the same on coding (42.4 vs 41.4); test both on your own repository before choosing.
Which has the bigger context window?
Gemini 2.5 Pro does, with 1.05M tokens against 128K.
How many benchmarks do Gemini 2.5 Pro and GPT-5.3 Chat share?
18 benchmarks have published results for both models. Gemini 2.5 Pro has 78 scored results on Noometry and GPT-5.3 Chat has 18.