Claude Fable 5 vs o3: which is better?

o3 leads on combined benchmark scores (95.1 vs 92) across general knowledge, coding, and math, as of 2026-07-27.

Which is cheaper, Claude Fable 5 or o3?

o3 is cheaper on a typical API workload, at roughly 5.6x lower cost than the alternative at published per-token rates.

Claude Fable 5 vs o3

o3 wins outright: higher benchmark scores and lower cost on a typical workload.

Updated 2026-07-27

Claude Fable 5

Anthropic · Closed

Combined index

OpenAI · Closed

95.1

Combined index

Leads

Benchmarks

General knowledge (MMLU)

91.8

91.6

Coding

89.2

95.8

Math

95.1

97.9

API pricing

$10.0 Input / 1M $2.0

$50.0 Output / 1M $8.0

$450.0 Monthly, est. $80.0

Monthly estimate assumes 20M input + 5M output tokens. Prices marked ~ are representative hosted rates for open-weight models and vary by provider. Run your own numbers in the cost calculator.

Claude Fable 5 costs → o3 costs → Full leaderboard → All comparisons →