Claude Sonnet 5.5 vs Gemini 3.6 Flash
| Spec | Claude Sonnet 5.5 | Gemini 3.6 Flash |
|---|---|---|
| Respan Index | 72.9 (#2) | 44.4 (#48) |
| Blended price per 1M | $2 | $0.75 |
| Context window | 1M | 1.0M |
| Input / output per 1M | $1 / $5 | $0.375 / $1.88 |
| Max output | 128K | 66K |
| Input | text, vision | text, vision, audio |
| Released | 2026-09-28 | 2026-07-21 |
Respan Index by category
Each category is scored 0 to 100, and how far ahead the winner is. Leads under a point are close to even.
| Category | Claude Sonnet 5.5 | Gemini 3.6 Flash |
|---|---|---|
| Coding | 78.6 Claude Sonnet 5.5 | 18.1 Gemini 3.6 Flash |
| Agents | 78.5 Claude Sonnet 5.5 | 57.3 Gemini 3.6 Flash |
| Reasoning | 79.0 Claude Sonnet 5.5 | 43.4 Gemini 3.6 Flash |
| Knowledge & language | 48.5 Claude Sonnet 5.5 | 65.3 Gemini 3.6 Flash |
| Human preference | 60.2 Claude Sonnet 5.5 | 54.5 Gemini 3.6 Flash |
Benchmarks both report
Claude Sonnet 5.5 leads on 16 of the 21 benchmarks both report. Higher is better. Each score links to where it was published.
| Benchmark | Claude Sonnet 5.5 | Gemini 3.6 Flash |
|---|---|---|
| Chess Puzzles (Epoch AI) | 59% | 42% |
| LMArena Agent (LMArena) | 0.1384 | -0.0445 |
| LMArena Elo | 1477 | 1483 |
| LMArena WebDev (LMArena) | 1770 | 1538 |
| LMArena Vision (LMArena) | 1265 | 1282 |
| APEX-Agents (Mercor) | 75.5% | 46.9% |
| FrontierMath Tier 4 v2 (Epoch AI) | 80.5% | 22% |
| FrontierMath Tiers 1-3 v2 (Epoch AI) | 88.8% | 58.9% |
| Furniture Assembly (Epoch AI) | 75% | 23.3% |
| GPQA Diamond | 95.6% | 94.1% |
| LiveBench Agentic Coding (LiveBench) | 56.3% | 43.4% |
| LiveBench Coding (LiveBench) | 91.4% | 77.9% |
| LiveBench Data Analysis (LiveBench) | 78.6% | 63% |
| LiveBench Instruction Following (LiveBench) | 70.5% | 75.4% |
| LiveBench Language (LiveBench) | 83.4% | 83.9% |
| LiveBench Mathematics (LiveBench) | 96.7% | 86.4% |
| LiveBench Reasoning (LiveBench) | 91.6% | 85.1% |
| Mystery Game Puzzles (Epoch AI) | 65% | 30% |
| OTIS Mock AIME 2024-2025 (Epoch AI) | 100% | 94.2% |
| SAGE (Vals AI) | 51.8% | 48.7% |
| SimpleQA Verified | 46.5% | 66.2% |
FAQ
Is Claude Sonnet 5.5 better than Gemini 3.6 Flash?
Claude Sonnet 5.5 scores 72.9 on the Respan Index (#2), ahead of Gemini 3.6 Flash at 44.4 (#48). Claude Sonnet 5.5 leads on 16 of the 21 benchmarks both report.
Which is cheaper, Claude Sonnet 5.5 or Gemini 3.6 Flash?
Claude Sonnet 5.5 lists at $1 input and $5 output per 1M tokens; Gemini 3.6 Flash at $0.375 and $1.88. Gemini 3.6 Flash is 2.7x cheaper per token at list price.
Which has the larger context window?
Claude Sonnet 5.5 accepts 1M tokens and Gemini 3.6 Flash 1.0M tokens.
Compare other models
- vsClaude Sonnet 5.5 vs Gemini 3.8 Flash
- vsGemini 3.8 Flash vs Gemini 3.6 Flash
- vsClaude Sonnet 5.5 vs Claude Opus 5.5
- vsClaude Sonnet 5.5 vs Claude Fable 5.1
- vsClaude Sonnet 5.5 vs GPT-6 Astra
- vsGemini 3.6 Flash vs Gemini 3.5 Flash
- vsGemini 3.6 Flash vs Qwen3.8-Flash-Next
- vsGemini 3.6 Flash vs Mistral Large 4