Model comparison
Claude Opus 5.5 vs Gemini 3.1 Flash Lite
Claude Opus 5.5 is the stronger model overall, scoring 68.5 to 40.4 on the Noometry Index. Gemini 3.1 Flash Lite costs 14× less per token, which makes it the better buy when Claude Opus 5.5's lead doesn't matter for your workload.
Last verified . 20 shared benchmarks.
GoogleSummary
- They share 20 benchmarks with published results for both. Claude Opus 5.5 scores higher in 10 categories and Gemini 3.1 Flash Lite in 0 categories; 10 gaps are clear of the uncertainty.
- The widest gap is in reasoning, where Claude Opus 5.5 leads 79.5 to 22.3.
- The biggest single-benchmark swing is NYT Connections (extended): 88.5% for Claude Opus 5.5 and 8.2% for Gemini 3.1 Flash Lite.
- Gemini 3.1 Flash Lite is cheaper at $0.25 / $1.50 per million input/output tokens, against $4 / $20 for Claude Opus 5.5.
- Gemini 3.1 Flash Lite accepts more context: 1.05M tokens versus 1M.
Side by side
| Claude Opus 5.5 | Gemini 3.1 Flash Lite | |
|---|---|---|
| Provider | Anthropic | |
| Noometry Index | 68.5 | 40.4 |
| Released | 2026-09-22 | 2026-03-03 |
| Weights | Proprietary | Proprietary |
| Context window | 1M | 1.05M |
| Max output | 128K | 66K |
| Input $ / M tokens | $4 | $0.25 |
| Output $ / M tokens | $20 | $1.50 |
| Results tracked | 35 | 38 |
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Category by category
Coding Claude Opus 5.5 leads
Claude Opus 5.5: 71.4 (#1), Gemini 3.1 Flash Lite: 37.5 (#179)
| Benchmark | Claude Opus 5.5 | Gemini 3.1 Flash Lite |
|---|---|---|
| LMArena WebDev | 1820 | 1256 |
| SciCode | 66.9% | 41.9% |
| LMArena Coding | 1545 | 1400 |
| FrontierCode | 54.4% | — |
| CursorBench | 57.8% | — |
| FrontierSWE | 62.3% | — |
| WeirdML | — | 52.2% |
| MirrorCode | 77.4% | — |
| ALE-Bench | — | 797.73 |
Agentic & Tool Use Claude Opus 5.5 leads
Claude Opus 5.5: 45.3 (#13), Gemini 3.1 Flash Lite: 29.9 (#72)
| Benchmark | Claude Opus 5.5 | Gemini 3.1 Flash Lite |
|---|---|---|
| APEX-Agents | 73.5% | — |
| DeepResearch Bench | — | 37.3% |
| GDP.pdf | 30.6% | — |
Reasoning Claude Opus 5.5 leads
Claude Opus 5.5: 79.5 (#2), Gemini 3.1 Flash Lite: 22.3 (#181)
| Benchmark | Claude Opus 5.5 | Gemini 3.1 Flash Lite |
|---|---|---|
| NYT Connections (extended) | 88.5% | 8.2% |
| CritPt | 31.7% | 1.1% |
| LMArena Hard Prompts | 1545 | 1407 |
| DTBench | 98.9% | 76.8% |
| LMCA | 68.2% | 35% |
| ARC-AGI-2 | 92.5% | — |
| Kagi LLM Benchmark | — | 67.2% |
| ARC-AGI-1 | 97.5% | — |
| Chess Puzzles | — | 25% |
| EnigmaEval | — | 3% |
| Thematic Generalization | — | 63.3% |
| EBR-Bench | 71.4% | — |
| Mystery Game Puzzles | 71% | — |
| Epoch Capabilities Index | — | 144.45 |
| ForecastBench | — | 54.4 |
Math Claude Opus 5.5 leads
Claude Opus 5.5: 92.4 (#2), Gemini 3.1 Flash Lite: 39.5 (#82)
| Benchmark | Claude Opus 5.5 | Gemini 3.1 Flash Lite |
|---|---|---|
| FrontierMath (Tiers 1-3) | 91.2% | 27.7% |
| OTIS Mock AIME 2024-2025 | 100% | 80% |
| FrontierMath Tier 4 | 95% | — |
| ProofBench | 100% | — |
| LMArena Math | — | 1427 |
Knowledge Claude Opus 5.5 leads
Claude Opus 5.5: 66.6 (#9), Gemini 3.1 Flash Lite: 41.7 (#95)
| Benchmark | Claude Opus 5.5 | Gemini 3.1 Flash Lite |
|---|---|---|
| GPQA Diamond | 90.6% | 81.8% |
| LMArena Expert | 1564 | 1397 |
| Humanity's Last Exam | — | 8.6% |
| SimpleQA Verified | 72.2% | — |
| Vectara Hallucination Rate | — | 8.2% |
Multimodal Claude Opus 5.5 leads
Claude Opus 5.5: 56.5 (#2), Gemini 3.1 Flash Lite: 38.7 (#57)
| Benchmark | Claude Opus 5.5 | Gemini 3.1 Flash Lite |
|---|---|---|
| LMArena Vision | — | 1240 |
| Furniture Assembly | 83.3% | — |
Multilingual Claude Opus 5.5 leads
Claude Opus 5.5: 59.8 (#1), Gemini 3.1 Flash Lite: 52.5 (#82)
| Benchmark | Claude Opus 5.5 | Gemini 3.1 Flash Lite |
|---|---|---|
| LMArena Non-English | 1513 | 1410 |
| LMArena Chinese | 1572 | 1461 |
| LMArena Russian | 1532 | 1420 |
| LMArena French | — | 1423 |
| LMArena German | — | 1429 |
| LMArena Japanese | — | 1411 |
| LMArena Korean | — | 1393 |
| LMArena Spanish | — | 1420 |
Instruction Following Claude Opus 5.5 leads
Claude Opus 5.5: 80.1 (#2), Gemini 3.1 Flash Lite: 72.9 (#126)
| Benchmark | Claude Opus 5.5 | Gemini 3.1 Flash Lite |
|---|---|---|
| LMArena Instruction Following | 1535 | 1376 |
Long Context Claude Opus 5.5 leads
Claude Opus 5.5: 47.3 (#18), Gemini 3.1 Flash Lite: 42.5 (#117)
| Benchmark | Claude Opus 5.5 | Gemini 3.1 Flash Lite |
|---|---|---|
| LMArena Longer Query | 1540 | 1394 |
Writing & Preference Claude Opus 5.5 leads
Claude Opus 5.5: 78.7 (#3), Gemini 3.1 Flash Lite: 61.0 (#90)
| Benchmark | Claude Opus 5.5 | Gemini 3.1 Flash Lite |
|---|---|---|
| LMArena Text | 1518 | 1416 |
| LMArena Creative Writing | 1538 | 1401 |
| LMArena Multi-Turn | 1520 | 1417 |
| EQ-Bench Creative Writing | 2050 | — |
Frequently asked questions
Is Claude Opus 5.5 better than Gemini 3.1 Flash Lite?
Claude Opus 5.5 is the stronger model overall, scoring 68.5 to 40.4 on the Noometry Index. Gemini 3.1 Flash Lite costs 14× less per token, which makes it the better buy when Claude Opus 5.5's lead doesn't matter for your workload.
Which is cheaper, Claude Opus 5.5 or Gemini 3.1 Flash Lite?
Gemini 3.1 Flash Lite is cheaper. It lists at $0.25 per million input tokens and $1.50 per million output tokens; Claude Opus 5.5 lists at $4 and $20.
Is Claude Opus 5.5 or Gemini 3.1 Flash Lite better for coding?
Claude Opus 5.5 scores higher on coding benchmarks: 71.4 versus 37.5 in the Noometry coding category.
Which has the bigger context window?
Gemini 3.1 Flash Lite does, with 1.05M tokens against 1M.
How many benchmarks do Claude Opus 5.5 and Gemini 3.1 Flash Lite share?
20 benchmarks have published results for both models. Claude Opus 5.5 has 35 scored results on Noometry and Gemini 3.1 Flash Lite has 38.