Claude Fable 5 vs o4-mini

Both are Reasoning-tier models, from Anthropic and OpenAI respectively. o4-mini is the cheaper choice overall at a 4:1 input:output ratio.

Which is cheaper

Input price: o4-mini is cheaper ($1.10 vs $10.00).
Output price: o4-mini is cheaper ($4.40 vs $50.00).
Blended, 4:1 input:output ratio: o4-mini is 90.2% cheaper ($1.76 vs $18.00 per weighted 1M tokens).

Side by side

Spec	Claude Fable 5	o4-mini
Provider	Anthropic	OpenAI
Tier	Reasoning	Reasoning
Context window	1M	200K
Max output	128K	100K
Input $/1M	$10.00	$1.10
Output $/1M	$50.00	$4.40
Cache read $/1M	$1.00	$0.275
Cache write $/1M	$12.50	—
Modalities	text, image	text, image

Claude Fable 5. 5-minute cache write shown; 1-hour cache write is $20/MTok.

Sources

Claude Fable 5 — verified August 29, 2026

o4-mini — verified August 29, 2026

Full Claude Fable 5 pricing page → · Full o4-mini pricing page →