Claude Opus 5.5, Anthropic's latest flagship model, has outscored Mistral AI's Mistral Large 4 Preview by 19.6 points on Artificial Analysis's Intelligence Index. The performance gap and cost implications are significant for AI developers and businesses.
TL;DR
- Claude Opus 5.5 scores 58 on the Intelligence Index, while Mistral Large 4 Preview scores 38.4.
- The cost of completing an index task is $1.13 for Mistral Large 4 and $5.98 for Claude Opus 5.5.
- Claude Opus 5.5 is optimized for long-horizon agentic work, while Mistral Large 4 is suited for high-volume, well-specified tasks.
What happened
Claude Opus 5.5, released on September 22, 2026, is Anthropic's current flagship model designed for complex, multi-step tasks. It is available on AWS, Google Cloud, and Microsoft Azure with zero data retention.
Mistral Large 4 Preview, announced on October 6, 2026, is Mistral AI's largest model to date, featuring 1.05 trillion total parameters and 52 billion active parameters. It is currently in public preview and is expected to release its weights by the end of October.
According to Artificial Analysis, Claude Opus 5.5 leads Mistral Large 4 by 19.6 points on the Intelligence Index, with scores of 58 and 38.4, respectively. The cost to complete an index task is significantly lower for Mistral Large 4 at $1.13 compared to $5.98 for Claude Opus 5.5.
Why it matters
For AI developers and businesses, the choice between Claude Opus 5.5 and Mistral Large 4 depends on the specific use case. Claude Opus 5.5 is ideal for complex, long-horizon tasks where accuracy is critical, while Mistral Large 4 is better suited for high-volume, well-specified tasks where cost efficiency is a priority.
The significant performance gap and cost difference highlight the importance of selecting the right model for the task at hand. Developers and businesses must weigh the benefits of higher accuracy against the costs to make informed decisions.
The competitive landscape for AI models is evolving rapidly. The performance and cost differences between Claude Opus 5.5 and Mistral Large 4 underscore the need for continuous evaluation and optimization of AI solutions.
Key facts
- Claude Opus 5.5 scores 58 on Artificial Analysis's Intelligence Index, while Mistral Large 4 Preview scores 38.4.
- The cost to complete an index task is $1.13 for Mistral Large 4 and $5.98 for Claude Opus 5.5.
- Claude Opus 5.5 is available on AWS, Google Cloud, and Microsoft Azure with zero data retention.
- Mistral Large 4 Preview is in public preview and is expected to release its weights by the end of October.
- Claude Opus 5.5 generated 260 million output tokens on its index run, while Mistral Large 4 Preview generated 200 million.
- Mistral Large 4 Preview is priced at $1.36 per million input tokens and $4.18 per million output tokens, with promotional pricing at $0.68 and $2.09, respectively.
- Claude Opus 5.5 is priced at $4 per million input tokens and $20 per million output tokens.
- Mistral Large 4 Preview is available on Mistral's own European infrastructure, while Claude Opus 5.5 is available on three major clouds.
Context
The AI model landscape is highly competitive, with continuous advancements and updates from leading companies. The performance and cost differences between models like Claude Opus 5.5 and Mistral Large 4 are critical factors for developers and businesses.
As AI models become more capable, the need for accurate benchmarking and cost analysis becomes increasingly important. Developers must carefully evaluate the trade-offs between performance and cost to select the most suitable model for their specific use cases.
The release of new AI models and updates to existing ones highlights the rapid pace of innovation in the field. Staying informed about the latest developments is essential for developers and businesses to leverage the most advanced AI solutions.
