Model comparison
Gemini 2.5 Flash vs GPT-5 Pro
GPT-5 Pro is the stronger model overall, scoring 46.4 to 39.3 on the Noometry Index. Gemini 2.5 Flash costs 49× less per token, which makes it the better buy when GPT-5 Pro's lead doesn't matter for your workload.
Last verified . 9 shared benchmarks.
GoogleSummary
- They share 9 benchmarks with published results for both. Gemini 2.5 Flash scores higher in 0 categories and GPT-5 Pro in 4 categories; 4 gaps are clear of the uncertainty.
- The widest gap is in reasoning, where GPT-5 Pro leads 38.9 to 18.1.
- The biggest single-benchmark swing is ARC-AGI-1: 33.3% for Gemini 2.5 Flash and 70.2% for GPT-5 Pro.
- Gemini 2.5 Flash is cheaper at $0.30 / $2.50 per million input/output tokens, against $15 / $120 for GPT-5 Pro.
- Gemini 2.5 Flash accepts more context: 1.05M tokens versus 400K.
Side by side
| Gemini 2.5 Flash | GPT-5 Pro | |
|---|---|---|
| Provider | OpenAI | |
| Noometry Index | 39.3 | 46.4 |
| Released | 2025-04-17 | 2025-10-06 |
| Weights | Proprietary | Proprietary |
| Context window | 1.05M | 400K |
| Max output | 66K | 272K |
| Input $ / M tokens | $0.30 | $15 |
| Output $ / M tokens | $2.50 | $120 |
| Results tracked | 54 | 12 |
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Category by category
Coding GPT-5 Pro leads
Gemini 2.5 Flash: 35.8 (#220), GPT-5 Pro: 44.0 (#80)
| Benchmark | Gemini 2.5 Flash | GPT-5 Pro |
|---|---|---|
| WeirdML | 41.9% | 60.4% |
| SWE-bench Verified (bash only) | 28.7% | — |
| Aider Polyglot | 55.1% | — |
| LMArena Coding | 1424 | — |
| ALE-Bench | 661.88 | — |
| AlgoTune | — | 1.31 |
Agentic & Tool Use Not comparable
Gemini 2.5 Flash: 30.8 (#74), GPT-5 Pro: —
| Benchmark | Gemini 2.5 Flash | GPT-5 Pro |
|---|---|---|
| Terminal-Bench | 17.1% | — |
| Berkeley Function Calling Leaderboard | 56.2% | — |
| TheAgentCompany | 41.1% | — |
| BALROG | 33.5% | — |
| Vending-Bench 2 | 548.84 | — |
Reasoning GPT-5 Pro leads
Gemini 2.5 Flash: 18.1 (#286), GPT-5 Pro: 38.9 (#62)
| Benchmark | Gemini 2.5 Flash | GPT-5 Pro |
|---|---|---|
| ARC-AGI-2 | 2.5% | 18.3% |
| SimpleBench | 41.2% | 61.6% |
| Kagi LLM Benchmark | 56.8% | 76.8% |
| ARC-AGI-1 | 33.3% | 70.2% |
| EnigmaEval | 2.7% | 18.8% |
| Epoch Capabilities Index | 143.03 | 150.28 |
| CritPt | 1.1% | — |
| LMArena Hard Prompts | 1422 | — |
| DTBench | 76.5% | — |
| LMCA | 27.5% | — |
| ForecastBench | 60.6 | — |
Math GPT-5 Pro leads
Gemini 2.5 Flash: 39.9 (#98), GPT-5 Pro: 48.5 (#63)
| Benchmark | Gemini 2.5 Flash | GPT-5 Pro |
|---|---|---|
| FrontierMath Tier 4 (v1) | 4.2% | 14.6% |
| FrontierMath (Tiers 1-3) | — | 55.8% |
| FrontierMath Tier 4 | — | 19.5% |
| OTIS Mock AIME 2024-2025 | 73.1% | — |
| Omni-MATH | 38.5% | — |
| LMArena Math | 1415 | — |
| FrontierMath (Feb 2025 set) | 4.8% | — |
Knowledge GPT-5 Pro leads
Gemini 2.5 Flash: 36.4 (#168), GPT-5 Pro: 56.7 (#42)
| Benchmark | Gemini 2.5 Flash | GPT-5 Pro |
|---|---|---|
| Humanity's Last Exam | 12.1% | 31.6% |
| MMLU-Pro | 63.9% | — |
| Confabulations | 16.8% | — |
| Vectara Hallucination Rate | 7.8% | — |
| GPQA (HELM) | 39% | — |
| LMArena Expert | 1426 | — |
Multimodal Not comparable
Gemini 2.5 Flash: 41.8 (#32), GPT-5 Pro: —
| Benchmark | Gemini 2.5 Flash | GPT-5 Pro |
|---|---|---|
| LMArena Vision | 1253 | — |
| GeoBench | 76% | — |
| VPCT | 46.2% | — |
| SpatialViz-Bench | 36.9% | — |
Multilingual Not comparable
Gemini 2.5 Flash: 52.3 (#88), GPT-5 Pro: —
| Benchmark | Gemini 2.5 Flash | GPT-5 Pro |
|---|---|---|
| LMArena Non-English | 1409 | — |
| LMArena Chinese | 1450 | — |
| LMArena French | 1433 | — |
| LMArena German | 1418 | — |
| LMArena Japanese | 1405 | — |
| LMArena Korean | 1385 | — |
| LMArena Russian | 1415 | — |
| LMArena Spanish | 1421 | — |
Instruction Following Not comparable
Gemini 2.5 Flash: 75.7 (#54), GPT-5 Pro: —
| Benchmark | Gemini 2.5 Flash | GPT-5 Pro |
|---|---|---|
| IFEval | 89.8% | — |
| LMArena Instruction Following | 1405 | — |
Long Context Not comparable
Gemini 2.5 Flash: 47.5 (#17), GPT-5 Pro: —
| Benchmark | Gemini 2.5 Flash | GPT-5 Pro |
|---|---|---|
| Fiction.LiveBench | 77.8% | — |
| LMArena Longer Query | 1419 | — |
Writing & Preference Not comparable
Gemini 2.5 Flash: 53.8 (#157), GPT-5 Pro: —
| Benchmark | Gemini 2.5 Flash | GPT-5 Pro |
|---|---|---|
| LMArena Text | 1417 | — |
| LMArena Creative Writing | 1400 | — |
| Short-Story Creative Writing | 76.5% | — |
| EQ-Bench Creative Writing | 1137 | — |
| WildBench | 81.7% | — |
| LMArena Multi-Turn | 1408 | — |
Frequently asked questions
Is Gemini 2.5 Flash better than GPT-5 Pro?
GPT-5 Pro is the stronger model overall, scoring 46.4 to 39.3 on the Noometry Index. Gemini 2.5 Flash costs 49× less per token, which makes it the better buy when GPT-5 Pro's lead doesn't matter for your workload.
Which is cheaper, Gemini 2.5 Flash or GPT-5 Pro?
Gemini 2.5 Flash is cheaper. It lists at $0.30 per million input tokens and $2.50 per million output tokens; GPT-5 Pro lists at $15 and $120.
Is Gemini 2.5 Flash or GPT-5 Pro better for coding?
GPT-5 Pro scores higher on coding benchmarks: 44.0 versus 35.8 in the Noometry coding category.
Which has the bigger context window?
Gemini 2.5 Flash does, with 1.05M tokens against 400K.
How many benchmarks do Gemini 2.5 Flash and GPT-5 Pro share?
9 benchmarks have published results for both models. Gemini 2.5 Flash has 54 scored results on Noometry and GPT-5 Pro has 12.