Model comparison
Gemini 3.1 Flash Lite vs GPT-5.5 Pro
GPT-5.5 Pro is the stronger model overall, scoring 64.3 to 40.4 on the Noometry Index. Gemini 3.1 Flash Lite costs 120× less per token, which makes it the better buy when GPT-5.5 Pro's lead doesn't matter for your workload.
Last verified . 8 shared benchmarks.
GoogleSummary
- They share 8 benchmarks with published results for both. Gemini 3.1 Flash Lite scores higher in 0 categories and GPT-5.5 Pro in 3 categories; 3 gaps are clear of the uncertainty.
- The widest gap is in reasoning, where GPT-5.5 Pro leads 73.6 to 22.3.
- The biggest single-benchmark swing is FrontierMath (Tiers 1-3): 27.7% for Gemini 3.1 Flash Lite and 87.7% for GPT-5.5 Pro.
- Gemini 3.1 Flash Lite is cheaper at $0.25 / $1.50 per million input/output tokens, against $30 / $180 for GPT-5.5 Pro.
- GPT-5.5 Pro accepts more context: 1.05M tokens versus 1.05M.
Side by side
| Gemini 3.1 Flash Lite | GPT-5.5 Pro | |
|---|---|---|
| Provider | OpenAI | |
| Noometry Index | 40.4 | 64.3 |
| Released | 2026-03-03 | 2026-04-23 |
| Weights | Proprietary | Proprietary |
| Context window | 1.05M | 1.05M |
| Max output | 66K | 128K |
| Input $ / M tokens | $0.25 | $30 |
| Output $ / M tokens | $1.50 | $180 |
| Results tracked | 38 | 14 |
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Category by category
Coding Not comparable
Gemini 3.1 Flash Lite: 37.5 (#179), GPT-5.5 Pro: —
| Benchmark | Gemini 3.1 Flash Lite | GPT-5.5 Pro |
|---|---|---|
| LMArena WebDev | 1256 | — |
| SciCode | 41.9% | — |
| WeirdML | 52.2% | — |
| LMArena Coding | 1400 | — |
| ALE-Bench | 797.73 | — |
Agentic & Tool Use Not comparable
Gemini 3.1 Flash Lite: 29.9 (#72), GPT-5.5 Pro: —
| Benchmark | Gemini 3.1 Flash Lite | GPT-5.5 Pro |
|---|---|---|
| DeepResearch Bench | 37.3% | — |
Reasoning GPT-5.5 Pro leads
Gemini 3.1 Flash Lite: 22.3 (#181), GPT-5.5 Pro: 73.6 (#7)
| Benchmark | Gemini 3.1 Flash Lite | GPT-5.5 Pro |
|---|---|---|
| CritPt | 1.1% | 30.6% |
| Chess Puzzles | 25% | 64% |
| DTBench | 76.8% | 96% |
| LMCA | 35% | 53.9% |
| Epoch Capabilities Index | 144.45 | 162.45 |
| ARC-AGI-2 | — | 84.6% |
| SimpleBench | — | 76.9% |
| Kagi LLM Benchmark | 67.2% | — |
| NYT Connections (extended) | 8.2% | — |
| ARC-AGI-1 | — | 96.5% |
| EnigmaEval | 3% | — |
| Thematic Generalization | 63.3% | — |
| LMArena Hard Prompts | 1407 | — |
| ForecastBench | 54.4 | — |
Math GPT-5.5 Pro leads
Gemini 3.1 Flash Lite: 39.5 (#82), GPT-5.5 Pro: 83.8 (#8)
| Benchmark | Gemini 3.1 Flash Lite | GPT-5.5 Pro |
|---|---|---|
| FrontierMath (Tiers 1-3) | 27.7% | 87.7% |
| OTIS Mock AIME 2024-2025 | 80% | 100% |
| FrontierMath Tier 4 | — | 78% |
| LMArena Math | 1427 | — |
| FrontierMath (Feb 2025 set) | — | 52.4% |
| FrontierMath Tier 4 (v1) | — | 39.6% |
Knowledge GPT-5.5 Pro leads
Gemini 3.1 Flash Lite: 41.7 (#95), GPT-5.5 Pro: 64.2 (#17)
| Benchmark | Gemini 3.1 Flash Lite | GPT-5.5 Pro |
|---|---|---|
| GPQA Diamond | 81.8% | 93.9% |
| Humanity's Last Exam | 8.6% | — |
| Vectara Hallucination Rate | 8.2% | — |
| LMArena Expert | 1397 | — |
Multimodal Not comparable
Gemini 3.1 Flash Lite: 38.7 (#57), GPT-5.5 Pro: —
| Benchmark | Gemini 3.1 Flash Lite | GPT-5.5 Pro |
|---|---|---|
| LMArena Vision | 1240 | — |
Multilingual Not comparable
Gemini 3.1 Flash Lite: 52.5 (#82), GPT-5.5 Pro: —
| Benchmark | Gemini 3.1 Flash Lite | GPT-5.5 Pro |
|---|---|---|
| LMArena Non-English | 1410 | — |
| LMArena Chinese | 1461 | — |
| LMArena French | 1423 | — |
| LMArena German | 1429 | — |
| LMArena Japanese | 1411 | — |
| LMArena Korean | 1393 | — |
| LMArena Russian | 1420 | — |
| LMArena Spanish | 1420 | — |
Instruction Following Not comparable
Gemini 3.1 Flash Lite: 72.9 (#126), GPT-5.5 Pro: —
| Benchmark | Gemini 3.1 Flash Lite | GPT-5.5 Pro |
|---|---|---|
| LMArena Instruction Following | 1376 | — |
Long Context Not comparable
Gemini 3.1 Flash Lite: 42.5 (#117), GPT-5.5 Pro: —
| Benchmark | Gemini 3.1 Flash Lite | GPT-5.5 Pro |
|---|---|---|
| LMArena Longer Query | 1394 | — |
Writing & Preference Not comparable
Gemini 3.1 Flash Lite: 61.0 (#90), GPT-5.5 Pro: —
| Benchmark | Gemini 3.1 Flash Lite | GPT-5.5 Pro |
|---|---|---|
| LMArena Text | 1416 | — |
| LMArena Creative Writing | 1401 | — |
| LMArena Multi-Turn | 1417 | — |
Frequently asked questions
Is Gemini 3.1 Flash Lite better than GPT-5.5 Pro?
GPT-5.5 Pro is the stronger model overall, scoring 64.3 to 40.4 on the Noometry Index. Gemini 3.1 Flash Lite costs 120× less per token, which makes it the better buy when GPT-5.5 Pro's lead doesn't matter for your workload.
Which is cheaper, Gemini 3.1 Flash Lite or GPT-5.5 Pro?
Gemini 3.1 Flash Lite is cheaper. It lists at $0.25 per million input tokens and $1.50 per million output tokens; GPT-5.5 Pro lists at $30 and $180.
Which has the bigger context window?
GPT-5.5 Pro does, with 1.05M tokens against 1.05M.
How many benchmarks do Gemini 3.1 Flash Lite and GPT-5.5 Pro share?
8 benchmarks have published results for both models. Gemini 3.1 Flash Lite has 38 scored results on Noometry and GPT-5.5 Pro has 14.