Claude Sonnet 5 vs Gemini 3.1 Pro: pricing and benchmarks
Both charge $2.00 per 1M input tokens. Claude Sonnet 5 is 17% cheaper on output tokens ($10.00 vs $12.00 per 1M). On our document Q&A workload (50,000 questions a month), Claude Sonnet 5 costs $1,100 a month versus $1,160 for Gemini 3.1 Pro, 5% less. Roughly tied. Claude Sonnet 5 scores 156.2 and Gemini 3.1 Pro scores 155.0 on the Epoch Capabilities Index, and their confidence intervals overlap.
Prices verified September 14, 2026.
Which should you choose?
Roughly tied. Claude Sonnet 5 scores 156.2 and Gemini 3.1 Pro scores 155.0 on the Epoch Capabilities Index, and their confidence intervals overlap.
Claude Sonnet 5 scores 53.8% on DeepSWE vs 11.7% for Gemini 3.1 Pro.
Claude Sonnet 5 scores 65.6% on FrontierMath (Tiers 1–3) vs 59.6% for Gemini 3.1 Pro.
Claude Sonnet 5 costs $4.00 per 1M tokens (3:1 input-to-output mix) vs $4.50 for Gemini 3.1 Pro, 11% less.
Claude Sonnet 5 delivers equal or higher overall capability for 11% less.
Pricing and specs
| Claude Sonnet 5 | Gemini 3.1 Pro | |
|---|---|---|
| Provider | Anthropic | |
| API model ID | claude-sonnet-5 | gemini-3.1-pro-preview |
| Input / 1M tokens | $2.00 | $2.00 |
| Cached input / 1M tokens | $0.20 | $0.20 |
| Output / 1M tokens | $10.00 | $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 Sonnet 5 | Gemini 3.1 Pro | |
|---|---|---|
| Epoch Capabilities Index | 156.2 | 155.0 |
| GPQA Diamond· Science reasoning | 87.4% | 92.6% |
| FrontierMath (Tiers 1–3)· Advanced math | 65.6% | 59.6% |
| SimpleQA Verified· Factual accuracy | 33.7% | 73.5% |
| ARC-AGI-2· Abstract reasoning | — | 77.1% |
| DeepSWE· Coding | 53.8% | 11.7% |
| APEX-Agents· Agentic work | 32.5% | 33.5% |
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 Sonnet 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. | $700.00 | $780.00 | Claude Sonnet 5 10% cheaper |
Document Q&A (RAG) 50,000 questions a month with ~8,000 tokens of retrieved context and ~600 output tokens each. | $1,100 | $1,160 | Claude Sonnet 5 5% 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. | $496.00 | $536.00 | Claude Sonnet 5 7% 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 Sonnet 5 vs Gemini 3.1 Pro cost calculator
- $1,100/mo$0.02 / request
- Gemini 3.1 ProGoogle$1,160/mo$0.02 / request
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 Sonnet 5 pricing notes
Anthropic’s best combination of speed and intelligence.
- The $2 / $10 launch price is now the standard price; the planned rise to $3 / $15 will not happen.
- Cache writes cost $2.50 (5-minute cache) or $4 (1-hour cache) per 1M tokens.
- Uses Anthropic’s newer tokenizer, which produces roughly 30% more tokens for the same text.
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 Sonnet 5 cheaper than Gemini 3.1 Pro?
- Both charge $2.00 per 1M input tokens. Claude Sonnet 5 is 17% cheaper on output tokens ($10.00 vs $12.00 per 1M). On our document Q&A workload (50,000 questions a month), Claude Sonnet 5 costs $1,100 a month versus $1,160 for Gemini 3.1 Pro, 5% less.
- Which is more capable, Claude Sonnet 5 or Gemini 3.1 Pro?
- Roughly tied. Claude Sonnet 5 scores 156.2 and Gemini 3.1 Pro scores 155.0 on the Epoch Capabilities Index, and their confidence intervals overlap.
- How much does Claude Sonnet 5 cost per 1M tokens?
- Claude Sonnet 5 costs $2.00 per 1M input tokens and $10.00 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 Sonnet 5 or Gemini 3.1 Pro?
- Gemini 3.1 Pro has the larger context window: 1.05M tokens versus 1M for Claude Sonnet 5.