Gemini 3.1 Pro vs Claude Opus 5
Google's flagship against Anthropic's, including the long-prompt surcharge only one of them charges.
Side by side
| Attribute | Gemini 3.1 Pro | Claude Opus 5 |
|---|---|---|
| Input, per 1M tokens | $2.00 | $5.00 |
| Output, per 1M tokens | $12.00 | $25.00 |
| Context window | 1,000,000 | 1,000,000 |
| Provider | Anthropic | |
| Tokenizer | Google tokenizer | Anthropic tokenizer |
| Long-context tier | above 200,000 | none |
| Retires | no date announced | no date announced |
Which to choose
- On cost, Gemini 3.1 Pro is 2.5x cheaper per million input tokens. On a workload that reads far more than it writes, that ratio is close to the whole difference in the bill.
- On capacity, both hold the same number of tokens, so neither constrains what you can send.
- On long prompts, at least one of these bills the entire request at an elevated rate past a threshold. A comparison made on short prompts can invert once you cross it.
What this page does not tell you. Which model produces better answers. That depends on your task, and this site has no benchmark data — everything above is drawn from published pricing and specifications. Compare quality by running your own prompts through both.
Common questions
- Is Gemini 3.1 Pro or Claude Opus 5 cheaper?
- Gemini 3.1 Pro is cheaper on input — $2.00 per million against $5.00, a difference of 2.5x. Output rates differ separately, and a workload heavy on generated text can reverse which one costs less overall.
- Which has the larger context window?
- Both hold 1,000,000 tokens, input and output combined.
- Can I compare them on my own prompt?
- Yes. The calculator counts any text against every model at once, so you can see both figures for your actual workload rather than for a generic example.