Quick Take

Agnes 2.5 Pro Alpha (released 2026-07-24) and Claude Fable 5 (released 2026-06-09) represent two distinct approaches to AI deployment. Agnes 2.5 Pro Alpha focuses on high-speed, low-cost utility, whereas Claude Fable 5 prioritizes high-end intelligence and reasoning depth.

Benchmark Read

Claude Fable 5 consistently outperforms Agnes 2.5 Pro Alpha across all shared metrics. In the Intelligence index, Claude Fable 5 scores 59.9 compared to 38.8 for Agnes. The coding gap is similarly pronounced, with Claude Fable 5 at 76.5 versus 58.8 for Agnes.

Specific benchmark results further highlight this disparity:

• GPQA: Claude Fable 5 (0.926) vs. Agnes 2.5 Pro Alpha (0.876)
• HLE: Claude Fable 5 (0.533) vs. Agnes 2.5 Pro Alpha (0.319)
• SciCode: Claude Fable 5 (0.602) vs. Agnes 2.5 Pro Alpha (0.422)
• LCR: Claude Fable 5 (0.7) vs. Agnes 2.5 Pro Alpha (0.637)

Claude Fable 5 also demonstrates advanced capabilities in specialized benchmarks, including IFBench (0.635), TerminalBench Hard (0.629), and TAU2 (0.985).

Cost and Speed

The economic profiles of these models are vastly different. Agnes 2.5 Pro Alpha is priced at a blended rate of $0.56/1M tokens ($0.45 input / $0.90 output). In contrast, Claude Fable 5 carries a blended cost of $20.00/1M tokens ($10.00 input / $50.00 output).

Performance metrics favor Agnes 2.5 Pro Alpha for real-time applications. It achieves an output speed of 133.925 tok/s with a time to first token of 1.929s. Claude Fable 5 is significantly slower, with an output speed of 58.886 tok/s and a time to first token of 65.797s.

Best Fit

Agnes 2.5 Pro Alpha is best suited for high-throughput environments, such as automated data processing or large-scale API integrations where latency and cost are critical. Claude Fable 5 is the optimal choice for complex reasoning, technical research, and tasks requiring the highest possible intelligence index, regardless of the higher cost.