Claude Fable 5 vs Claude Opus 4.8
Compare Claude Fable 5 and Claude Opus 4.8 on the metrics that decide an agent workload.
| Metric | Claude Fable 5 | Claude Opus 4.8 |
|---|---|---|
| Provider | Anthropic | Anthropic |
| Input / 1M | $10.00 | $5.00 |
| Output / 1M | $50.00 | $25.00 |
| Cache read / 1M | $1.00 (−90%) | $0.50 (−90%) |
| Reuse-adj @55% | $16.29 | $8.14 |
| Context | 1M | 1M |
| Cache capture | 93% | 93% |
| Warm TTFT | 280ms (−70%) | 240ms (−68%) |
| Quality index | 98 | 97 |
Teal marks the better value in each row. Reuse-adjusted assumes 55% prefix reuse and a 25% output share.
Pick Claude Fable 5 when it scores higher on the composite quality index.
Pick Claude Opus 4.8 when it is cheaper once prefix reuse is priced in, it answers faster on warm cache hits.
Claude Fable 5 leads on quality while Claude Opus 4.8 leads on reuse-adjusted cost. Send latency- and budget-sensitive volume to Claude Opus 4.8 and reserve Claude Fable 5 for the hard requests. Zumik's aliases route between them automatically under policy.
Claude Fable 5 vs Claude Opus 4.8, answered.
Is Claude Fable 5 or Claude Opus 4.8 cheaper?
At 55% prefix reuse, Claude Fable 5 blends to about $16.29 per 1M tokens and Claude Opus 4.8 to about $8.14. Claude Opus 4.8 is cheaper on that basis.
Which has the larger context window?
Claude Fable 5 has the larger window: 1M vs 1M tokens.
Which captures more reuse?
Claude Fable 5 shows higher measured cache capture (93% vs 93%) in the Zumik corpus.
Let an alias pick for you.
Route to whichever model wins under current policy automatically. Zumik resolves the alias to the best fit per request, so you never hard-code a loser.