Claude Sonnet 5.5 vs Gemini 3.6 Flash: Specs & Benchmark Comparison
Claude Sonnet 5.5 is developed by Anthropic, while Gemini 3.6 Flash comes from Google. Gemini 3.6 Flash was released in July 2026, and Claude Sonnet 5.5 followed 2 months later in September 2026.
The two models share 2 published benchmarks. Claude Sonnet 5.5 leads on 2 of them. The widest gaps are on SWE-Bench Pro, where Claude Sonnet 5.5 scores 81.3% against 58.7%; DeepSWE 1.1, where Claude Sonnet 5.5 scores 71.0% against 49.0%. Averaged across everything we track, Claude Sonnet 5.5 sits at 67.4% and Gemini 3.6 Flash at 68.0%.
Gemini 3.6 Flash is the cheaper API at $1.50 per million input tokens and $7.50 per million output tokens, about 33% below Claude Sonnet 5.5 at $2 and $10. Both accept a context window of about 1M tokens. Both accept text and images as input.
| Characteristic | Claude Sonnet 5.5 | Gemini 3.6 Flash |
|---|---|---|
| Company | Anthropic | |
| Release Date | September 28, 2026 | July 21, 2026 |
| Parameters | — | — |
| Multimodal | Yes | Yes |
| Context (input) | 1.0M | 1.0M |
| Context (output) | 128K | 66K |
| Input Price / 1M | $2.00 | $1.50 |
| Output Price / 1M | $10.00 | $7.50 |
| Average Score | 67.4% | 68.0% |
| Benchmarks | ||
| SWE-Bench Pro | 81.3% | 58.7% |
| DeepSWE 1.1 | 71.0% | 49.0% |
Visual Benchmark Comparison
Verdict
Both models show equal results — the choice depends on your specific use case.
Both models show comparable average scores: Claude Sonnet 5.5 — 0.7, Gemini 3.6 Flash — 0.7.
Gemini 3.6 Flash is 1.3x cheaper: input $1.50/1M vs $2.00/1M tokens.
Same context size: 1M tokens.
Claude Sonnet 5.5 is newer: released 9/28/2026 vs 7/21/2026.
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Frequently Asked Questions
Which is better for coding — Claude Sonnet 5.5 or Gemini 3.6 Flash?
Which model is cheaper — Claude Sonnet 5.5 or Gemini 3.6 Flash?
Which has a larger context window — Claude Sonnet 5.5 or Gemini 3.6 Flash?
The Claude Sonnet 5.5 and Gemini 3.6 Flash comparison is updated for 2026. Data includes benchmark results, API pricing, context window size and other specifications. For more detailed information, visit the Claude Sonnet 5.5 or Gemini 3.6 Flash page. See also the complete list of AI model comparisons.