# Claude Sonnet 5.5 vs Gemini 2.5 Flash-Lite

> Claude Sonnet 5.5 is the stronger model overall, scoring 61.9 to 37.0 on the Noometry Index. Gemini 2.5 Flash-Lite costs 23× less per token, which makes it the better buy when Claude Sonnet 5.5's lead doesn't matter for your workload.

- Canonical page: https://noometry.com/compare/claude-sonnet-5-5-vs-gemini-2-5-flash-lite
- Last updated: 2026-10-12
- Shared benchmarks: 15

## Summary

- They share 15 benchmarks with published results for both. Claude Sonnet 5.5 scores higher in 10 categories and Gemini 2.5 Flash-Lite in 0 categories; 10 gaps are clear of the uncertainty.
- The widest gap is in math, where Claude Sonnet 5.5 leads 87.9 to 38.0.
- Gemini 2.5 Flash-Lite is cheaper at $0.10 / $0.40 per million input/output tokens, against $2 / $10 for Claude Sonnet 5.5.
- Gemini 2.5 Flash-Lite accepts more context: 1.05M tokens versus 1M.

## Snapshot

| | Claude Sonnet 5.5 | Gemini 2.5 Flash-Lite |
|---|---|---|
| Provider | Anthropic | Google |
| Noometry Index | 61.9 | 37.0 |
| Rank | 10 | 211 |
| Context | 1M | 1.05M |
| Input $/M | $2 | $0.10 |
| Output $/M | $10 | $0.40 |
| Weights | Proprietary | Proprietary |

## Coding

- Claude Sonnet 5.5: 67.3 (#6)
- Gemini 2.5 Flash-Lite: 38.5 (#173)

| Benchmark | Claude Sonnet 5.5 | Gemini 2.5 Flash-Lite |
|---|---|---|
| LMArena Coding | 1513 | 1373 |
| ALE-Bench | 1,819 | 325.9 |
| FrontierCode | 52.1% | — |
| CursorBench | 55.5% | — |
| LMArena WebDev | 1774 | — |
| FrontierSWE | 61.9% | — |
| SciCode | 61% | — |
| WeirdML | — | 35.2% |

## Agentic & Tool Use

- Claude Sonnet 5.5: 45.0 (#16)
- Gemini 2.5 Flash-Lite: 28.0 (#96)

| Benchmark | Claude Sonnet 5.5 | Gemini 2.5 Flash-Lite |
|---|---|---|
| APEX-Agents | 75.5% | — |
| Berkeley Function Calling Leaderboard | — | 36.9% |

## Reasoning

- Claude Sonnet 5.5: 54.0 (#28)
- Gemini 2.5 Flash-Lite: 22.2 (#205)

| Benchmark | Claude Sonnet 5.5 | Gemini 2.5 Flash-Lite |
|---|---|---|
| LMArena Hard Prompts | 1495 | 1377 |
| Epoch Capabilities Index | 165.03 | 133.94 |
| Kagi LLM Benchmark | — | 40.5% |
| NYT Connections (extended) | 80.5% | — |
| CritPt | 31.4% | — |
| Mystery Game Puzzles | 65% | — |
| DTBench | — | 62.8% |
| LMCA | — | 18.1% |

## Math

- Claude Sonnet 5.5: 87.9 (#6)
- Gemini 2.5 Flash-Lite: 38.0 (#144)

| Benchmark | Claude Sonnet 5.5 | Gemini 2.5 Flash-Lite |
|---|---|---|
| LMArena Math | 1510 | 1373 |
| FrontierMath (Tiers 1-3) | 88.8% | — |
| FrontierMath Tier 4 | 80.5% | — |
| OTIS Mock AIME 2024-2025 | 100% | — |
| ProofBench | 100% | — |
| Omni-MATH | — | 48% |
| FrontierMath Erdős | 2.9% | — |

## Knowledge

- Claude Sonnet 5.5: 66.0 (#12)
- Gemini 2.5 Flash-Lite: 32.5 (#210)

| Benchmark | Claude Sonnet 5.5 | Gemini 2.5 Flash-Lite |
|---|---|---|
| LMArena Expert | 1540 | 1373 |
| GPQA Diamond | 95.6% | — |
| SimpleQA Verified | 46.5% | — |
| MMLU-Pro | — | 53.7% |
| Vectara Hallucination Rate | — | 3.3% |
| GPQA (HELM) | — | 30.9% |

## Multimodal

- Claude Sonnet 5.5: 51.5 (#6)
- Gemini 2.5 Flash-Lite: 29.1 (#114)

| Benchmark | Claude Sonnet 5.5 | Gemini 2.5 Flash-Lite |
|---|---|---|
| LMArena Vision | 1289 | 1198 |
| VPCT | — | 30% |
| Furniture Assembly | 75% | — |

## Multilingual

- Claude Sonnet 5.5: 55.3 (#30)
- Gemini 2.5 Flash-Lite: 49.3 (#134)

| Benchmark | Claude Sonnet 5.5 | Gemini 2.5 Flash-Lite |
|---|---|---|
| LMArena Non-English | 1452 | 1369 |
| LMArena Chinese | 1522 | 1404 |
| LMArena Russian | 1451 | 1373 |
| LMArena French | — | 1388 |
| LMArena German | — | 1389 |
| LMArena Japanese | — | 1359 |
| LMArena Korean | — | 1360 |
| LMArena Spanish | — | 1396 |

## Instruction Following

- Claude Sonnet 5.5: 78.3 (#11)
- Gemini 2.5 Flash-Lite: 70.0 (#168)

| Benchmark | Claude Sonnet 5.5 | Gemini 2.5 Flash-Lite |
|---|---|---|
| LMArena Instruction Following | 1495 | 1367 |
| IFEval | — | 81% |

## Long Context

- Claude Sonnet 5.5: 45.9 (#28)
- Gemini 2.5 Flash-Lite: 33.3 (#262)

| Benchmark | Claude Sonnet 5.5 | Gemini 2.5 Flash-Lite |
|---|---|---|
| LMArena Longer Query | 1498 | 1373 |
| Fiction.LiveBench | — | 47.2% |

## Writing & Preference

- Claude Sonnet 5.5: 66.0 (#40)
- Gemini 2.5 Flash-Lite: 56.8 (#135)

| Benchmark | Claude Sonnet 5.5 | Gemini 2.5 Flash-Lite |
|---|---|---|
| LMArena Text | 1471 | 1379 |
| LMArena Creative Writing | 1465 | 1367 |
| LMArena Multi-Turn | 1474 | 1366 |
| WildBench | — | 81.8% |

## FAQ

### Is Claude Sonnet 5.5 better than Gemini 2.5 Flash-Lite?

Claude Sonnet 5.5 is the stronger model overall, scoring 61.9 to 37.0 on the Noometry Index. Gemini 2.5 Flash-Lite costs 23× less per token, which makes it the better buy when Claude Sonnet 5.5's lead doesn't matter for your workload.

### Which is cheaper, Claude Sonnet 5.5 or Gemini 2.5 Flash-Lite?

Gemini 2.5 Flash-Lite is cheaper. It lists at $0.10 per million input tokens and $0.40 per million output tokens; Claude Sonnet 5.5 lists at $2 and $10.

### Is Claude Sonnet 5.5 or Gemini 2.5 Flash-Lite better for coding?

Claude Sonnet 5.5 scores higher on coding benchmarks: 67.3 versus 38.5 in the Noometry coding category.

### Which has the bigger context window?

Gemini 2.5 Flash-Lite does, with 1.05M tokens against 1M.

### How many benchmarks do Claude Sonnet 5.5 and Gemini 2.5 Flash-Lite share?

15 benchmarks have published results for both models. Claude Sonnet 5.5 has 32 scored results on Noometry and Gemini 2.5 Flash-Lite has 33.