Claude Opus 5 vs Gemini 3.1 Pro
Claude Opus 5 and Gemini 3.1 Pro compared on current per-token rates, context window, and capabilities — both callable through one OpenAI-compatible endpoint with per-request cost traces.
Claude Opus 5 vs Gemini 3.1 Pro: rates, context window, and capabilities
| Spec | Claude Opus 5 | Gemini 3.1 Pro |
|---|---|---|
| Input / 1M tokens | $2.25 | $6.00 |
| Output / 1M tokens | $11.25 | $18.00 |
| Cached input / 1M tokens | $0.38 | $6.00 |
| Context window | 1.0M | 1.0M |
| Capabilities | — | Chat, Streaming, Tool calling, Vision |
| Detail page | Claude Opus 5 | Gemini 3.1 Pro |
What does 1M tokens cost on Claude Opus 5 vs Gemini 3.1 Pro?
For a workload of 1M input plus 1M output tokens at current rates: Claude Opus 5 comes to $13.50, Gemini 3.1 Pro comes to $24.00 — Claude Opus 5 is about 44% cheaper on this mix. Real workloads skew heavily toward input tokens, so weigh the input rate by your own ratio; prompt-cache hits bill at the cached-input rate where supported.
Switch between Claude Opus 5 and Gemini 3.1 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:
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-opus-5", "messages": [{"role": "user", "content": "Hello"}]}'
# Same request, other model — change one string:
# "model": "google/gemini-3.1-pro-preview"FAQ
Is Claude Opus 5 cheaper than Gemini 3.1 Pro?
At current posted rates, Claude Opus 5 is the cheaper of the two (input $2.25 vs $6.00, output $11.25 vs $18.00 per 1M tokens). Rates change; the /models page is the live source of truth.
Can I switch between Claude Opus 5 and Gemini 3.1 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.