Claude Fable 5 Benchmark Cost Analysis: High Performance vs. High Expense
A benchmark reveals Claude Fable 5 is the most expensive model to run, costing over 1.7x more than the next highest, with doubled API and cache prices compared to its predecessor.
Practical Summary
This analysis breaks down the concrete cost implications of using the new Claude Fable 5 model. It compares its benchmark performance and pricing against previous Claude models and GPT-5.5, highlighting the significant financial trade-off for state-of-the-art intelligence.
Why It Matters
For teams optimizing AI tool costs, this data provides a clear case study. It quantifies the premium for top-tier performance, helping developers and budget holders decide if the intelligence gains justify the substantial increase in operational expenditure, especially for cost-sensitive applications like agentic coding with heavy cache usage.
Understanding the Benchmark Cost
The Artificial Analysis Intelligence Index is a benchmark suite used to evaluate model capabilities. Running this benchmark on Claude Fable 5 cost approximately $6,200. This is a direct measure of computational expense, not an API call price, illustrating the model's resource intensity during evaluation.
Performance vs. Cost Trade-off
Claude Fable 5 achieved the highest intelligence score of 60 on the benchmark. However, this performance comes at a steep premium. It scored 4 points higher than Claude Opus 4.8 but cost 1.7 times more to run. Compared to GPT-5.5 (score: 55), it scored 5 points higher but cost 2.2 times more to benchmark.
API and Cache Pricing Implications
The list price for API access to Claude Fable 5 is $10 per million input tokens and $50 per million output tokens. This is double the price of Claude Opus 4.8. Furthermore, cache pricing—a critical factor for long, stateful workflows like agentic coding—also doubled: cache reads cost $1 per million tokens versus $0.50 for Opus, and cache writes cost $12.50 per million tokens versus $6.25. These price increases directly impact the cost of building and running applications.