Head to Head: Claude Fable 5 vs ChatGPT 5.5

The open-source coding agent says Claude Fable 5 planned better, while GPT-5.5 matched it on execution at lower cost.

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Why it matters

Kilo's test reframes coding-agent economics around task routing: premium models may be most valuable for planning, not for every token of implementation.

Two AI figures labeled Claude Fable 5 and ChatGPT 5.5 face a shared code screen, comparing performance metrics and execution results in a coding-focused scene.

Kilo Code published a fresh model test Saturday that lands at an inconvenient moment for Anthropic: Claude Fable 5, the model Kilo found strongest at planning, is already offline after a U.S. export-control directive.…

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