Prices → Compare → Claude Opus 5 vs Gemini 3.1 Pro
Claude Opus 5 vs Gemini 3.1 Pro: API cost compared
Claude Opus 5 lists at $5.000 in / $25.00 out per 1M tokens. Gemini 3.1 Pro lists at $2.000 in / $12.00. Sticker price only tells you so much — below is what each actually costs across eight production workloads.
Side by side
| Claude Opus 5 | Gemini 3.1 Pro | |
|---|---|---|
| Provider | Anthropic | |
| Input per 1M | $5.000 | $2.000 |
| Output per 1M | $25.00 | $12.00 |
| Cached input per 1M | $0.500 | not published |
| Context window | 200k | 1M |
| Blended per 1M (3:1) | $10.00 | $4.500 |
Monthly cost by workload
Caching applied at each workload's typical hit rate. This is where the two models actually separate.
| Workload | Claude Opus 5 | Gemini 3.1 Pro | Cheaper | Difference |
|---|---|---|---|---|
| Customer support chatbot | $644.50 | $390.00 | Gemini 3.1 Pro | $254.50 (39%) |
| RAG document Q&A | $920.00 | $464.00 | Gemini 3.1 Pro | $456.00 (50%) |
| Coding agent | $462.50 | $344.00 | Gemini 3.1 Pro | $118.50 (26%) |
| Bulk summarization | $6,730 | $2,880 | Gemini 3.1 Pro | $3,850 (57%) |
| Structured data extraction | $8,725 | $5,000 | Gemini 3.1 Pro | $3,725 (43%) |
| Long-form content generation | $1,073 | $520.00 | Gemini 3.1 Pro | $553.00 (52%) |
| Email triage agent | $2,012 | $1,360 | Gemini 3.1 Pro | $652.50 (32%) |
| Translation pipeline | $7,024 | $3,330 | Gemini 3.1 Pro | $3,694 (53%) |
How to read this
Gemini 3.1 Pro is cheaper on the majority of these workloads, but "majority" is not the decision. The output:input price ratio is 5.0 for Claude Opus 5 and 6.0 for Gemini 3.1 Pro. If your traffic is output-heavy — long-form drafting, translation — the model with the lower output price wins regardless of what the input price suggests. If you are input-heavy — RAG, bulk summarization, agents re-reading a codebase — the cached input rate matters more than either headline number.
Cost is also not the only axis. This site does not benchmark quality, latency, or rate limits, and a model that is 3x cheaper but needs two attempts per task is not cheaper. Use these numbers to size a bill, then validate on your own evals.
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Cost calculator
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| Model | In /1M | Out /1M | Monthly | vs best |
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