Claude Opus 5.5 vs Gemini 3.1 Pro: pricing and benchmarks
Gemini 3.1 Pro is 50% cheaper on input tokens ($2.00 vs $4.00 per 1M). Gemini 3.1 Pro is 40% cheaper on output tokens ($12.00 vs $20.00 per 1M). On our document Q&A workload (50,000 questions a month), Gemini 3.1 Pro costs $1,160 a month versus $2,200 for Claude Opus 5.5, 47% less. Claude Opus 5.5 scores 166.8 on the Epoch Capabilities Index vs 154.7 for Gemini 3.1 Pro.
Which should you choose?
Claude Opus 5.5 scores 166.8 on the Epoch Capabilities Index vs 154.7 for Gemini 3.1 Pro.
Claude Opus 5.5 scores 91.2% on FrontierMath (Tiers 1–3) vs 59.6% for Gemini 3.1 Pro.
Gemini 3.1 Pro costs $4.50 per 1M tokens (3:1 input-to-output mix) vs $8.00 for Claude Opus 5.5, 44% less.
A trade-off: Claude Opus 5.5 is 12.2 ECI points more capable but costs 1.8x as much as Gemini 3.1 Pro.
Pricing and specs
| Claude Opus 5.5 | Gemini 3.1 Pro | |
|---|---|---|
| Provider | Anthropic | |
| API model ID | claude-opus-5-5 | gemini-3.1-pro-preview |
| Input / 1M tokens | $4.00 | $2.00 |
| Cached input / 1M tokens | $0.20 | $0.20 |
| Output / 1M tokens | $20.00 | $12.00 |
| Long-context rates | — | $4.00 in / $18.00 out above 200K prompt tokens |
| Context window | 1M tokens | 1.05M tokens |
| Max output | 128K tokens | 66K tokens |
| Batch discount | 50% off | — |
Benchmarks
| Claude Opus 5.5 | Gemini 3.1 Pro | |
|---|---|---|
| Epoch Capabilities Index | 166.8 | 154.7 |
| GPQA Diamond· Science reasoning | 90.6% | 94.4% |
| FrontierMath (Tiers 1–3)· Advanced math | 91.2% | 59.6% |
| SimpleQA Verified· Factual accuracy | 72.2% | 73.5% |
| ARC-AGI-2· Abstract reasoning | 93.3% | 77.1% |
| DeepSWE· Coding | — | 11.7% |
| APEX-Agents· Agentic work | 73.5% | 35.3% |
Source: Epoch AI, best recorded result per model (CC BY 4.0). A dash means no published score. See all benchmarks
Monthly cost for real workloads
| Workload | Claude Opus 5.5 | Gemini 3.1 Pro | Difference |
|---|---|---|---|
Support chatbot 100,000 replies a month, ~1,500 input tokens (system prompt + history) and ~400 output tokens each. | $1,400 | $780.00 | Gemini 3.1 Pro 44% cheaper |
Document Q&A (RAG) 50,000 questions a month with ~8,000 tokens of retrieved context and ~600 output tokens each. | $2,200 | $1,160 | Gemini 3.1 Pro 47% cheaper |
Coding agent 10,000 agent steps a month, ~40,000 input tokens each (70% read from the prompt cache) and ~2,000 output tokens. | $936.00 | $536.00 | Gemini 3.1 Pro 43% cheaper |
Cached chatbot The same 100,000-reply support chatbot, but 60% of each prompt (system prompt + conversation history) is served from the prompt cache. | $1,058 | $618.00 | Gemini 3.1 Pro 42% cheaper |
Meeting notes 10,000 meetings a month summarized from ~12,000-token transcripts, ~1,000 output tokens each. | $680.00 | $360.00 | Gemini 3.1 Pro 47% cheaper |
Bulk translation 200,000 short translations a month, ~800 input and ~800 output tokens each. | $3,840 | $2,240 | Gemini 3.1 Pro 42% cheaper |
Content moderation 1,000,000 classifications a month, ~400 input tokens and ~80 output tokens each. | $3,200 | $1,760 | Gemini 3.1 Pro 45% cheaper |
Article drafting 300 long-form articles a month written from a ~4,000-token brief and outline, ~5,000 output tokens each. | $34.80 | $20.40 | Gemini 3.1 Pro 41% cheaper |
Code review bot 30,000 pull-request reviews a month, ~5,000 input tokens each (30% cached repository context) and ~700 output tokens. | $849.00 | $471.00 | Gemini 3.1 Pro 45% cheaper |
Invoice extraction 100,000 documents a month parsed into structured JSON, ~1,200 input and ~250 output tokens each. | $980.00 | $540.00 | Gemini 3.1 Pro 45% cheaper |
Estimates use standard list prices and ignore cache-write surcharges. Different tokenizers can count the same text differently, so test with your own prompts.
Claude Opus 5.5 vs Gemini 3.1 Pro cost calculator
- $1,160/mo$0.02 / req
- Claude Opus 5.5Anthropic$2,200/mo$0.04 / req
Standard-tier list prices. Long-context rates apply automatically where the provider publishes a threshold. Excludes cache-write surcharges, taxes, batch and volume discounts.
Claude Opus 5.5 pricing notes
Anthropic’s recommended default model for most workloads, with adaptive thinking always on.
- Cache reads cost 5% of the input price, against 10% on Claude Opus 5 and Sonnet 5.
- Cache writes cost $5 (5-minute cache) or $8 (1-hour cache) per 1M tokens.
- Fast mode costs $8 input / $40 output per 1M tokens.
- US-only inference (inference_geo: "us") costs 1.1x.
Gemini 3.1 Pro pricing notes
Google’s Gemini 3.1 Pro model, currently offered as a preview.
- Prompts over 200K tokens are billed at $4 input / $18 output per 1M tokens.
- No free tier on the Gemini API.
- Output price includes thinking tokens.
Frequently asked questions
- Is Claude Opus 5.5 cheaper than Gemini 3.1 Pro?
- Gemini 3.1 Pro is 50% cheaper on input tokens ($2.00 vs $4.00 per 1M). Gemini 3.1 Pro is 40% cheaper on output tokens ($12.00 vs $20.00 per 1M). On our document Q&A workload (50,000 questions a month), Gemini 3.1 Pro costs $1,160 a month versus $2,200 for Claude Opus 5.5, 47% less.
- Which is more capable, Claude Opus 5.5 or Gemini 3.1 Pro?
- Claude Opus 5.5 scores 166.8 on the Epoch Capabilities Index vs 154.7 for Gemini 3.1 Pro.
- How much does Claude Opus 5.5 cost per 1M tokens?
- Claude Opus 5.5 costs $4.00 per 1M input tokens and $20.00 per 1M output tokens, and $0.20 per 1M cached input tokens on Anthropic’s standard tier.
- How much does Gemini 3.1 Pro cost per 1M tokens?
- Gemini 3.1 Pro costs $2.00 per 1M input tokens and $12.00 per 1M output tokens, and $0.20 per 1M cached input tokens on Google’s standard tier.
- Which has the larger context window, Claude Opus 5.5 or Gemini 3.1 Pro?
- Gemini 3.1 Pro has the larger context window: 1.05M tokens versus 1M for Claude Opus 5.5.