Claude Opus 5 (Fast) vs Gemini 3.1 Pro Preview Custom Tools
| Signal | Claude Opus 5 (Fast) | Delta | Gemini 3.1 Pro Preview Custom Tools |
|---|---|---|---|
Capabilities | 100 | -- | |
Pricing | 50 | -38 | |
Context window size | 95 | 0 | |
Recency | 100 | -- | |
Output Capacity | 85 | +5 | |
Benchmarks | 0 | -91 | |
| Overall Result | 1 wins | of 6 | 3 wins |
Score History
95.1
current score
Claude Opus 5 (Fast)
right now
92.2
current score
Claude Opus 5 (Fast)
Anthropic
Gemini 3.1 Pro Preview Custom Tools
Gemini 3.1 Pro Preview Custom Tools saves you $2700.00/month
That's $32400.00/year compared to Claude Opus 5 (Fast) at your current usage level of 100K calls/month.
| Metric | Claude Opus 5 (Fast) | Gemini 3.1 Pro Preview Custom Tools | Winner |
|---|---|---|---|
| Overall Score | 95 | 92 | Claude Opus 5 (Fast) |
| Rank | #2 | #10 | Claude Opus 5 (Fast) |
| Quality Rank | #2 | #10 | Claude Opus 5 (Fast) |
| Adoption Rank | #2 | #10 | Claude Opus 5 (Fast) |
| Parameters | -- | -- | -- |
| Context Window | 1000K | 1049K | Gemini 3.1 Pro Preview Custom Tools |
| Pricing | $10.00/$50.00/M | $2.00/$12.00/M | -- |
| Signal Scores | |||
| Capabilities | 100 | 100 | Claude Opus 5 (Fast) |
| Pricing | 50 | 88 | Gemini 3.1 Pro Preview Custom Tools |
| Context window size | 95 | 96 | Gemini 3.1 Pro Preview Custom Tools |
| Recency | 100 | 100 | Claude Opus 5 (Fast) |
| Output Capacity | 85 | 80 | Claude Opus 5 (Fast) |
| Benchmarks | -- | 92 | Gemini 3.1 Pro Preview Custom Tools |
Our score (0-100) is driven by benchmark performance (90%) from Arena Elo ratings, MMLU, GPQA, HumanEval, SWE-bench, and 15+ standardized evaluations. Capabilities and context window serve as tiebreakers (10%). Learn more about our methodology.
Scores 95/100 (rank #2), placing it in the top 100% of all 290 models tracked.
Scores 92/100 (rank #10), placing it in the top 97% of all 290 models tracked.
With only a 3-point gap, these models are in the same performance tier. The practical difference in output quality is minimal - your choice should depend on pricing, latency requirements, and specific feature needs.
Choose Claude Opus 5 (Fast) when you need:
- Step-by-step reasoning and chain-of-thought problem solving
Choose Gemini 3.1 Pro Preview Custom Tools when you need:
- High-volume production workloads where API costs must be minimized
- Step-by-step reasoning and chain-of-thought problem solving
Gemini 3.1 Pro Preview Custom Tools offers 77% better value per quality point. At 1M tokens/day, you'd spend $210.00/month with Gemini 3.1 Pro Preview Custom Tools vs $900.00/month with Claude Opus 5 (Fast) - a $690.00 monthly difference.
Both models have comparable response speeds. For most applications, the latency difference is negligible.
When latency matters most: Interactive chatbots, IDE code completion, real-time translation, and user-facing applications where response time directly impacts experience. For batch processing, background summarization, or offline analysis, latency is less critical.
Code generation & review
Based on overall model capabilities and architecture for coding tasks like generating functions, debugging, and refactoring
Customer support chatbot
Suitable for user-facing chat with competitive response times. Gemini 3.1 Pro Preview Custom Tools also offers lower per-token costs for high-volume support
Long document analysis
Larger context window (1049K tokens) can process longer documents, contracts, and research papers in a single pass
Batch data extraction
Lower output pricing ($12.00/M) reduces costs when processing thousands of records daily
Creative writing & content
Higher overall composite score (95/100) correlates with better nuance, coherence, and style in long-form content
Image understanding & OCR
Supports vision input - can analyze screenshots, diagrams, photos, and scanned documents directly
Claude Opus 5 (Fast) and Gemini 3.1 Pro Preview Custom Tools are extremely close in overall performance (only 2.8999999999999915 points apart). Your best choice depends entirely on which specific strengths matter most for your use case.
By Use Case
Best for Quality
Claude Opus 5 (Fast)
Marginally better benchmark scores; both are excellent
Best for Cost
Gemini 3.1 Pro Preview Custom Tools
77% lower pricing; better value at scale
Best for Reliability
Claude Opus 5 (Fast)
Higher uptime and faster response speeds
Best for Prototyping
Claude Opus 5 (Fast)
Stronger community support and better developer experience
Best for Production
Claude Opus 5 (Fast)
Wider enterprise adoption and proven at scale
by Anthropic
- Choose for Quality - Marginally better benchmark scores; both are excellent
- Choose for Reliability - Higher uptime and faster response speeds
- Choose for Prototyping - Stronger community support and better developer experience
- Choose for Production - Wider enterprise adoption and proven at scale
by Google
- Choose for Cost - 77% lower pricing; better value at scale
| Capability | Claude Opus 5 (Fast) | Gemini 3.1 Pro Preview Custom Tools |
|---|---|---|
| Vision (Image Input) | ||
| Function Calling | ||
| Streaming | ||
| JSON Mode | ||
| Reasoning | ||
| Web Search | ||
| Image Output |
Claude Opus 5 (Fast)
Anthropic
Gemini 3.1 Pro Preview Custom Tools
Gemini 3.1 Pro Preview Custom Tools saves you $60.00/month
That's 77% cheaper than Claude Opus 5 (Fast) at 1,000 tokens/request and 100 requests/day.
Assumes 60% input / 40% output token ratio per request. Actual costs may vary based on your usage pattern.
| Parameter | Claude Opus 5 (Fast) | Gemini 3.1 Pro Preview Custom Tools |
|---|---|---|
| Context Window | 1M | 1.0M |
| Max Output Tokens | 128,000 | 65,536 |
| Open Source | No | No |
| Created | Jul 24, 2026 | Feb 25, 2026 |