Claude Opus 5.5 vs Gemini 3.1 Pro
A side-by-side look at Claude Opus 5.5 from Anthropic and Gemini 3.1 Pro from Google: list prices, context windows, licensing and capabilities, with monthly costs worked out for three common workloads.
The short version
- Lower list price: Gemini 3.1 Pro, about 1.8× cheaper on a blended basis (three parts input to one part output).
- Larger context window: Gemini 3.1 Pro (1M vs 1M tokens).
- Inputs: Claude Opus 5.5 accepts text, images, pdf; Gemini 3.1 Pro accepts text, images, video, audio, pdf.
- Newer release: Claude Opus 5.5 (September 22, 2026).
Specs side by side
| Claude Opus 5.5 | Gemini 3.1 Pro | |
|---|---|---|
| Provider | Anthropic | |
| Released | Sep 22, 2026 | Feb 19, 2026 |
| Status | Current | Preview |
| Weights and license | Closed Proprietary | Closed Proprietary |
| Tier | Frontier | Frontier |
| Context window | 1M | 1M |
| Max output | 125K | 64K |
| Input per 1M tokens | $4 | $2 |
| Output per 1M tokens | $20 | $12 |
| Cached input per 1M | $0.20 | $0.20 |
| Input types | Text, Images, PDF | Text, Images, Video, Audio, PDF |
| Reasoning mode | Yes | Yes |
| Tool calling | Yes | Yes |
| Parameters | Undisclosed | Undisclosed |
Highlighted cells are better on that line: lower price or larger limit. List prices, standard tier, checked October 10, 2026.
What they cost for real workloads
| Workload (monthly) | Claude Opus 5.5 | Gemini 3.1 Pro | Difference |
|---|---|---|---|
| Support chatbot30,000 conversations a month, 2,000 input and 400 output tokens each | $480 | $264 | Gemini 3.1 Pro saves $216 |
| Document summaries2,000 documents a month, 12,000 input and 800 output tokens each | $128 | $67 | Gemini 3.1 Pro saves $61 |
| Coding agent1,000 tasks a month, 60,000 input and 6,000 output tokens each | $360 | $192 | Gemini 3.1 Pro saves $168 |
Standard rates without caching or batch discounts. Try your own volumes.
Choose Claude Opus 5.5 if
- you mainly need it for agents, enterprise, which Anthropic emphasizes for this model
- anthropic's recommended default for most workloads
- 1M-token context with no long-context surcharge
Choose Gemini 3.1 Pro if
- you mainly need it for multimodal, research, which Google emphasizes for this model
- cost per token is a deciding factor
- you need more than 1M tokens of context in one request
- your inputs include audio, video
- 1,048,576-token input limit and 65,536-token output limit
Our take
Both are positioned for coding, long documents, reasoning. On list price the gap is about 1.8×, which matters most for high-volume, input-heavy workloads. Quality differences shift with every release, so treat this page as a shortlist tool: run 20-50 of your real tasks through both, score the outputs, and divide the bill by the number of tasks each one got right.
Read the full profiles: Claude Opus 5.5 and Gemini 3.1 Pro. For help designing that test, see how to read LLM benchmarks.
Frequently asked questions
Which is cheaper, Claude Opus 5.5 or Gemini 3.1 Pro?
Gemini 3.1 Pro has the lower list price: $2 input and $12 output per million tokens, versus $4 and $20. Discounts for caching and batch processing can change the real bill, so price your own token mix.
Which has the bigger context window?
Gemini 3.1 Pro accepts 1M tokens, compared with 1M for Claude Opus 5.5.
Can I run Claude Opus 5.5 or Gemini 3.1 Pro on my own hardware?
Claude Opus 5.5 is closed, so only through hosted APIs. Gemini 3.1 Pro is closed, so only through hosted APIs.
Is Claude Opus 5.5 better than Gemini 3.1 Pro?
It depends on the task. Public benchmarks and arena rankings move with every release and rarely match a specific workload. Use the specs here to shortlist, then test both on your own prompts and compare accuracy, latency and cost per correct answer.
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