Compare verified pricing and model limits for premium escalation from Anthropic's current Sonnet tier. The cost example uses a long-context research workload and does not assume equal model quality.
Sonnet 5 is the lower-cost current-generation starting point; Fable 5 is the premium route worth testing on the hardest unresolved tasks. The decision should be revisited when Sonnet 5 introductory pricing ends.
| Decision factor | Claude Fable 5 | Claude Sonnet 5 |
|---|---|---|
| Current standard token price | $10 input and $50 output per million tokens | $2 input and $10 output per million tokens through August 31, 2026 |
| Later Sonnet 5 price | No temporary pricing window is tracked | $3 input and $15 output per million tokens from September 1, 2026 |
| Tracked limits | 1M context and 128k maximum output | 1M context and 128k maximum output |
Prices are USD per 1M tokens under each model's verified default profile.
| Field | Claude Fable 5 | Claude Sonnet 5 |
|---|---|---|
| API access provider | Anthropic | Anthropic |
| API model ID | claude-fable-5 | claude-sonnet-5 |
| Input / 1M | $10.00 | $2.00 |
| Cached input / 1M | $1.00 | $0.20 |
| Output / 1M | $50.00 | $10.00 |
| Context window | 1,000,000 tokens | 1,000,000 tokens |
| Maximum output | 128,000 tokens | 128,000 tokens |
| Accepted input | text, image | text, image |
150,000 input and 5,000 output tokens per request, 2,000 monthly requests, and 10% cached input.
Cost result: Claude Sonnet 5 is $2,584.00 lower per month for these assumptions. This is a price comparison, not a model-quality ranking.
Models whose tracked context window is below the scenario input are excluded from the compatible-model table.
Latency, reliability, output quality, retries, regional processing, and provider-specific tool charges can change the practical decision.