AiGanakClaude Opus 5.5 vs Claude Fable 5.1: API pricing
Claude Opus 5.5 is cheaper: a typical support answer costs $0.019 against $0.046 on Claude Fable 5.1 at list prices checked 26 October 2026.
Claude Opus 5.5: $4 input / $20 output per 1M tokens. Claude Fable 5.1: $10 / $50.
Prices side by side
Sources: Anthropic, checked 26 October 2026. Full details: Claude Opus 5.5 · Claude Fable 5.1.
| Claude Opus 5.5 | Claude Fable 5.1 | |
|---|---|---|
| Input | $4 | $10 |
| Cached input | $0.2 | $0.25 |
| Output | $20 | $50 |
| Batch input / output | $2 / $10 | $5 / $25 |
| Cache write | $5 | $12.50 |
| Long prompts | No long-prompt surcharge listed | No long-prompt surcharge listed |
| Announced change | None announced | None announced |
Cost per request
Token counts are stated so you can check the arithmetic.
| Task | Tokens | Claude Opus 5.5 | Claude Fable 5.1 |
|---|---|---|---|
| Chat reply | 2,000 input tokens, none cached, 300-token reply | $0.014 | $0.035 |
| Support answer | 6,000 input tokens (4,000 cached instructions and help text), 500-token answer | $0.019 | $0.046 |
| Document summary | 20,000-token document, no caching, 800-token summary | $0.096 | $0.240 |
Monthly cost of support answers
| Answers per month | Claude Opus 5.5 | Claude Fable 5.1 | Difference |
|---|---|---|---|
| 10,000 | $188 | $460 | $272 |
| 100,000 | $1,880 | $4,600 | $2,720 |
| 1,000,000 | $18,800 | $46,000 | $27,200 |
Price per token is only part of the story: the model that answers in fewer tokens, or needs fewer retries, can be cheaper in practice. Test both on your own requests before switching.
Claude Opus 5.5 vs Claude Fable 5.1: pricing questions
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Is Claude Opus 5.5 cheaper than Claude Fable 5.1?
Claude Opus 5.5 is cheaper: a typical support answer costs $0.019 against $0.046 on Claude Fable 5.1 at list prices checked 26 October 2026.
How much more does Claude Fable 5.1 cost than Claude Opus 5.5?
For a support answer with 6,000 input tokens (4,000 cached) and a 500-token reply, Claude Fable 5.1 costs 2.4× more than Claude Opus 5.5: $46.00 against $18.80 per 1,000 answers.
What do Claude Opus 5.5 and Claude Fable 5.1 cost with batch processing?
Batch prices per million tokens: Claude Opus 5.5 $2 input / $10 output, Claude Fable 5.1 $5 / $25. Batch requests return within 24 hours.
Should I switch from Claude Opus 5.5 to Claude Fable 5.1?
Only if quality holds on your own examples. Price per token is one factor; how many tokens each model uses for your task, and how often its answers need a retry, decide the real cost. Test both on 50 to 100 real requests before switching.
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