# Claude Sonnet 5 vs Gemini 3 Pro

> Markdown mirror of https://router.one/models/compare/claude-sonnet-5-vs-gemini-3-pro for AI assistants and crawlers. Router One is an OpenAI-compatible LLM API gateway.

Claude Sonnet 5 is lower on a 1M-input + 1M-output mix (about 31% less), but Gemini 3 Pro has the lower input rate — real workloads skew toward input. Both carry a 1.05M context window. Claude Sonnet 5 answers on /v1/chat/completions and /v1/messages (Claude Code); Gemini 3 Pro on /v1/chat/completions.

Claude Sonnet 5 and Gemini 3 Pro compared on current per-token rates, context window, and capabilities — both callable through one OpenAI-compatible endpoint with per-request cost traces.

## Claude Sonnet 5 vs Gemini 3 Pro: rates, context window, and capabilities

| Spec | Claude Sonnet 5 | Gemini 3 Pro |
| --- | --- | --- |
| Input / 1M tokens | $0.90 | $0.882 |
| Output / 1M tokens | $4.50 | $7.00 |
| Cached input / 1M tokens | $0.15 | $0.882 |
| Context window | 1.05M | 1.05M |
| Capabilities | Chat, Streaming, Tool calling, Vision | Chat, Streaming, Tool calling, Vision |
| Detail page | [Claude Sonnet 5](https://router.one/models/claude-sonnet-5) | [Gemini 3 Pro](https://router.one/models/gemini-3-pro-preview-11-2025) |

## What does 1M tokens cost on Claude Sonnet 5 vs Gemini 3 Pro?

For a workload of 1M input plus 1M output tokens at current rates: Claude Sonnet 5 comes to $5.40, Gemini 3 Pro comes to $7.882 — Claude Sonnet 5 is about 31% cheaper on this mix. Real workloads skew heavily toward input tokens, so weigh the input rate by your own ratio; the cached-input row above is the posted catalog rate for that model.

## Switch between Claude Sonnet 5 and Gemini 3 Pro without changing code

Both models are behind the same OpenAI-compatible endpoint, so an A/B test is a one-string change — same key, same code, and every request traced with tokens, cost, and latency in the dashboard:

`compare.sh`

```bash
curl https://api.router.one/v1/chat/completions \
  -H "Authorization: Bearer sk-your-router-one-key" \
  -H "Content-Type: application/json" \
  -d '{"model": "anthropic/claude-sonnet-5", "messages": [{"role": "user", "content": "Hello"}]}'

# Same request, other model — change one string:
#   "model": "google/gemini-3-pro-preview-11-2025"
```

## FAQ

### Is Claude Sonnet 5 cheaper than Gemini 3 Pro?

At current posted rates, Claude Sonnet 5 is the cheaper of the two (input $0.90 vs $0.882, output $4.50 vs $7.00 per 1M tokens). Rates change; the /models page is the live source of truth.

### Can I switch between Claude Sonnet 5 and Gemini 3 Pro without changing code?

Yes. Both are served through the same OpenAI-compatible endpoint, so switching is changing the model string in the request — the key, base URL, and request shape stay identical.

### Where do these numbers come from?

Specs and prices on this page render from the live Router One catalog — the same data as the /models page — and refresh with it. Pricing methodology is documented on /pricing-methodology. Rates on this page were read from the live catalog on 2026-08-26 (UTC) and refresh within the hour.

## More comparisons

- [GPT-5.5 vs Claude Sonnet 5](https://router.one/models/compare/gpt-5-5-vs-claude-sonnet-5)
- [GPT-5.4 vs Gemini 3 Pro](https://router.one/models/compare/gpt-5-4-vs-gemini-3-pro)
- [GPT-5.3 Codex Spark vs Claude Sonnet 5](https://router.one/models/compare/gpt-5-3-codex-spark-vs-claude-sonnet-5)
- [Claude Opus 4.8 vs Claude Sonnet 5](https://router.one/models/compare/claude-opus-4-8-vs-claude-sonnet-5)

## See also

- Canonical page: https://router.one/models/compare/claude-sonnet-5-vs-gemini-3-pro
- All model comparisons: https://router.one/models/compare
- All models & prices: https://router.one/models (markdown: https://router.one/models.md)
- Pricing: https://router.one/pricing
- Claude API access: https://router.one/cheap-claude-api
- Gemini API in China: https://router.one/gemini-api-china
- Cost calculator: https://router.one/llm-cost-calculator
- Pricing methodology: https://router.one/pricing-methodology