Kimi K3 vs Fable 5: same code, a third of the price, four times slower

The author ran Moonshot’s Kimi K3 and Anthropic’s Fable 5 through three real coding tasks in the Rust fd repo: a bug fix, a refactor, and a new flag. The prompts were identical; only the model and CLI changed, Kimi Code 0.27.0 against Claude Code 2.1.212.

The output matched. On the bug, both deleted the same line in src/main.rs, the diffs came out byte for byte, and all 70 tests passed. The refactor produced a config_builder.rs module and cleared 264 tests in both runs, and both shipped a working --count flag.

On API pricing, Kimi K3 runs $3 per million input tokens and $15 per million output; Fable 5 is $10 and $50. Across the three tasks Kimi cost $2.13 to Fable’s $5.98, but burned 3.3 million tokens against 2.4 million. On the clock Fable finished in 6 minutes 49 seconds; Kimi took about 28 minutes 18 seconds.