Claude Sonnet 5.5 vs Gemini 3.8 Flash
How Anthropic's Claude Sonnet 5.5 and Google AI's Gemini 3.8 Flash differ on paper, from the specs each provider publishes.
Compare them on your promptBoth answer side by side, free with your own API keys.
Key differences
- Gemini 3.8 Flash accepts a larger context window: 1.05M tokens versus 1M for Claude Sonnet 5.5.
- Claude Sonnet 5.5 can write longer replies, up to 128K output tokens against 66K.
- Claude Sonnet 5.5 lists extended thinking support that Gemini 3.8 Flash does not.
Side by side
| Spec | Claude Sonnet 5.5 | Gemini 3.8 Flash |
|---|---|---|
| Provider | Anthropic | Google AI |
| Released | September 2026 | September 2026 |
| Context window | 1M tokens | 1.05M tokens |
| Max output | 128K tokens | 66K tokens |
| Reasoning model | Yes | Yes |
| Price per 1M tokens (in / out) | $2 / $10 | See provider |
| Capabilities | Image input, Reasoning, Coding, Tool calling, Structured output, Extended thinking, Streaming | Image input, Reasoning, Coding, Tool calling, Structured output, Streaming |
Specs as published by each provider. Benchmarks and output quality aren't covered here; the best test is your own prompts.
Specs only go so far. Ask both.
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