Claude Opus 5.5 vs Claude Fable 5.1: benchmarks and token cost

This comparison uses Claude Opus 5.5 (Max, Default Fallback) and Claude Fable 5.1 (Xhigh, Default Fallback). It reports the captured benchmark data, with no new hands-on test.

Two Anthropic generations with different effort labels

Opus records 58.4 on the captured index, compared with Fable’s 49.7. Opus also has lower listed input and output token rates in this snapshot. Preserve the Max versus Xhigh settings when reproducing the comparison. The figures support screening the candidates; they do not establish that every existing Fable workflow can be migrated without behavior or quality checks.

How to read the table

The intelligence index is an aggregate measurement, not a percentage of correct answers in your application. Input and output prices are separate rates per million tokens. Coding and math indices are unavailable in this capture and must not be read as zero. Compare first-token latency separately from output-token throughput, and use the same model effort settings for a trial. Choose using task quality, total time and the cost of accepted results; provider features and deployment requirements need their own checks.