| Claude Fable 5.1 | GPT-5.4 Mini | |
|---|---|---|
| Input, per 1M tokens | $10.00 | $0.75 |
| Output, per 1M tokens | $50.00 | $4.50 |
| Context window | 1M | 400K |
| Classification or routing (600 tokens in, 10 out), per 1,000 | $6.50 | $0.495 |
| Chat reply (2,000 in, 400 out), per 1,000 | $40.00 | $3.30 |
| Retrieval-augmented answer (8,000 in, 500 out), per 1,000 | $105 | $8.25 |
| Confidence signal | no | no |
| Tool calling | yes | yes |
Which one should carry your traffic?
If GPT-5.4 Mini answers your requests as well as Claude Fable 5.1, moving that traffic saves 92% on chat-shaped requests. Averages cannot tell you whether it does for your requests. GPT-5.4 Mini does not expose a confidence signal through OpenRouter, so Gimbix would test it as a full replacement rather than a first answer.
Claude Fable 5.1 profile · GPT-5.4 Mini profile · Measure it on your traffic