Claude Fable 5.1 vs Claude Opus 5.5: API cost comparison
For a typical chatbot (1,500 input + 400 output tokens, 100,000 requests a month), Claude Opus 5.5 is 60% cheaper: $1,658 vs $4,145 for Claude Fable 5.1. Paste your own prompt below to compare the exact cost of your workload.
0 characters0 words0 tokens (GPT o200k)
| Model | Per month |
|---|---|
| Claude Fable 5.1 | |
| Claude Opus 5.5 |
≈ = estimated token count: only OpenAI publishes its tokenizer. Claude counts use Anthropic’s published ratios; use the count_tokens API for an exact number.
Price per million tokens
USD, standard tier. Prices checked on October 28, 2026.
| Claude Fable 5.1 | Claude Opus 5.5 | |
|---|---|---|
| Input | $10 | $4 |
| Output | $50 | $20 |
| Cached input | $0.25 | $0.2 |
| Cache write (5 min) | $12.5 | $5 |
| Long prompts | Same price at any length | Same price at any length |
| Batch API | 50% off | 50% off |
| Provider | Anthropic (Claude) | Anthropic (Claude) |
Monthly cost for common workloads
| Workload | Claude Fable 5.1 | Claude Opus 5.5 |
|---|---|---|
| Chatbot 1,500 input + 400 output tokens, 100,000 requests a month | $4,145 | $1,658 |
| Document Q&A (RAG) 8,000 input + 500 output tokens, half the input cached, 20,000 requests a month | $1,673 | $680 |
| Long-document summary 150,000 input + 2,000 output tokens, 1,000 requests a month | $2,245 | $898 |
| Bulk classification (Batch API) 500 input + 20 output tokens, 1 million requests a month, Batch API where available | $4,075 | $1,630 |
Token counts are converted per model: the same text becomes a different number of tokens on each provider (see below). The cheaper option in each row is highlighted.
Frequently asked questions
Is Claude Fable 5.1 cheaper than Claude Opus 5.5?
Per million tokens, Claude Fable 5.1 costs $10 / $50 (input / output) and Claude Opus 5.5 costs $4 / $20. For a typical chatbot workload (1,500 input + 400 output tokens, 100,000 requests a month), Claude Opus 5.5 is 60% cheaper: $1,658 vs $4,145 for Claude Fable 5.1. Token counts differ between providers, so compare the cost of the same prompt rather than the price per token.
How much do Claude Fable 5.1 and Claude Opus 5.5 cost per million tokens?
Claude Fable 5.1: $10 / $50 for input / output, $0.25 for cached input. Claude Opus 5.5: $4 / $20, $0.2 for cached input. Prices in US dollars, standard tier, checked on October 28, 2026.
Do Claude Fable 5.1 and Claude Opus 5.5 count tokens the same way?
Claude Fable 5.1 uses Anthropic's newer tokenizer, which produces about 30% more tokens than earlier Claude models. We estimate about 1.43× the GPT o200k count for the same text. Claude Opus 5.5 uses Anthropic's newer tokenizer, which produces about 30% more tokens than earlier Claude models. We estimate about 1.43× the GPT o200k count for the same text.
Do Claude Fable 5.1 and Claude Opus 5.5 have a Batch API discount?
Both do: Claude Fable 5.1 gets 50% off and Claude Opus 5.5 50% off for requests sent through the Batch API, which may take up to 24 hours.
Related comparisons
- Claude Opus 5.5 vs GPT-6 Astra
- Claude Opus 5.5 vs Gemini 4 Argon
- Claude Opus 5.5 vs Claude Sonnet 5.5
- Claude Opus 5.5 vs Claude Opus 5