# Claude Sonnet 4.5 Thinking vs Gemini 3.1 Flash-Lite

> Side-by-side benchmark comparison for Claude Sonnet 4.5 Thinking and Gemini 3.1 Flash-Lite across agentic, coding, multimodal, knowledge, reasoning, multilingual, and math tasks.

- Canonical page: https://benchlm.ai/compare/claude-sonnet-4-5-thinking-vs-gemini-3-1-flash-lite
- Last updated: September 4, 2026

- Shared sourced benchmarks: 1
- HTML indexing: indexable
- Ranking lane: BenchAlign v5

## Quick Verdict

Evidence is too thin for a benchmark verdict: Claude Sonnet 4.5 Thinking and Gemini 3.1 Flash-Lite share only 1 sourced benchmark row.

## Summary

- Only 1 shared sourced benchmark row is available. That is not enough for a broad capability verdict, so this mirror does not name an overall winner.
- Gemini 3.1 Flash-Lite has the larger published context window at 1M.

## Model Snapshot

| Property | Claude Sonnet 4.5 Thinking | Gemini 3.1 Flash-Lite |
|----------|----------|----------|
| Creator | Anthropic | Google |
| Type | Proprietary | Proprietary |
| Reasoning | Reasoning | Non-Reasoning |
| Context | 200K | 1M |
| Independent public score (not head-to-head) | null | 56.13 |
| Benchmarks Covered | 1 | 8 |
| Pricing (input/output) | N/A | $0.25 / $1.50 |

## Category Breakdown

### Agentic

- Winner: Insufficient shared evidence
- Claude Sonnet 4.5 Thinking public-lane score: Coming soon
- Gemini 3.1 Flash-Lite public-lane score: 43.3 (Estimated · #105/151)

| Benchmark | Claude Sonnet 4.5 Thinking | Gemini 3.1 Flash-Lite | Winner |
|-----------|-----------|-----------|--------|
| Gert Labs | Coming soon | 38.46% | Coming soon |
| Terminal-Bench 2.1 (Vals) | Coming soon | 34.1% | Coming soon |

### Coding

- Winner: Insufficient shared evidence
- Claude Sonnet 4.5 Thinking public-lane score: Coming soon
- Gemini 3.1 Flash-Lite public-lane score: 38.1 (Estimated · #148/183)

| Benchmark | Claude Sonnet 4.5 Thinking | Gemini 3.1 Flash-Lite | Winner |
|-----------|-----------|-----------|--------|
| Vibe Code Bench | 22.62% | 0.00% | Claude Sonnet 4.5 Thinking |
| LiveCodeBench (Vals) | Coming soon | 80.1% | Coming soon |
| SWE-bench (Vals) | Coming soon | 62.8% | Coming soon |

### Multimodal & Grounded

- Winner: Insufficient shared evidence
- Claude Sonnet 4.5 Thinking public-lane score: Coming soon
- Gemini 3.1 Flash-Lite public-lane score: 37.5 (Unranked · 1 rankable row)

| Benchmark | Claude Sonnet 4.5 Thinking | Gemini 3.1 Flash-Lite | Winner |
|-----------|-----------|-----------|--------|
| CharXiv | Coming soon | 73.2% | Coming soon |

### Knowledge

- Winner: Insufficient shared evidence
- Claude Sonnet 4.5 Thinking public-lane score: Coming soon
- Gemini 3.1 Flash-Lite public-lane score: 51.8 (Estimated · #79/181)

| Benchmark | Claude Sonnet 4.5 Thinking | Gemini 3.1 Flash-Lite | Winner |
|-----------|-----------|-----------|--------|
| GPQA Diamond (Vals) | Coming soon | 81.1% | Coming soon |
| MMLU-Pro (Vals) | Coming soon | 86.2% | Coming soon |

## FAQ

### Is there enough evidence to pick between Claude Sonnet 4.5 Thinking and Gemini 3.1 Flash-Lite?

Not yet. The models share only 1 sourced benchmark row, so this mirror reports the available measurements and metadata without naming a broad winner.

### What can I compare safely on this page?

Published pricing, context windows, model type, and individual shared benchmark rows are directly comparable. Independent overall scores and non-overlapping benchmark coverage are labeled separately and should not be read as a controlled head-to-head result.

## Related Comparisons

- [Claude Sonnet 4.5 Thinking vs Claude Sonnet 4.5](/compare/claude-sonnet-4-5-vs-claude-sonnet-4-5-thinking)
- [Gemini 3.1 Flash-Lite vs Claude Sonnet 4.5](/compare/claude-sonnet-4-5-vs-gemini-3-1-flash-lite)
- [Claude Sonnet 4.5 Thinking vs Claude Fable 5.1](/compare/claude-fable-5-1-vs-claude-sonnet-4-5-thinking)
- [Gemini 3.1 Flash-Lite vs Claude Fable 5.1](/compare/claude-fable-5-1-vs-gemini-3-1-flash-lite)

## Explore More

- [Claude Sonnet 4.5 Thinking profile](/models/claude-sonnet-4-5-thinking)
- [Gemini 3.1 Flash-Lite profile](/models/gemini-3-1-flash-lite)
- [Compare Pricing](/llm-pricing)
- [Alternative Finder](/tools/alternative-finder)
- [LLM Selector](/tools/llm-selector)
- [Overall Rankings](/best/overall)