Claude Fable 5.1 vs Inception: Mercury 2.5
anthropic/claude-fable-5.1 · inception/mercury-2.5
As of November 5, 2026, Inception: Mercury 2.5 is the cheaper API on UberLLM: $0.0460 per million input tokens and $0.1725 per million output, versus $0.5410 / $2.70 for Claude Fable 5.1, about 93% less when output is 3 tokens for every input token. These are the best prices on the market right now. Both work with one OpenAI-compatible key and UberLLM adds no fee. Choose Inception: Mercury 2.5 to cut cost; choose Claude Fable 5.1 when context size wins. Claude Fable 5.1 carries the larger context window (1,000,000 vs 260,000 tokens), which can matter for long-document work.
Claude Fable 5.1 vs Inception: Mercury 2.5, side by side
| Spec | Claude Fable 5.1 | Inception: Mercury 2.5 |
|---|---|---|
| Price · input / 1M | $0.5410 | $0.0460 |
| Price · output / 1M | $2.70 | $0.1725 |
| Context length | 1,000,000 | 260,000 |
| Max output tokens | 128,000 | 65,536 |
| Input modalities | text, image, file | text |
| Output modalities | text | text |
| Tools / functions | Yes | Yes |
| Vision (image input) | Yes | — |
| Reasoning | Yes | Yes |
| % off list | 94.6% off | — |
Best prices on UberLLM right now. No UberLLM fee on requests; adding credit by card costs 5.5% + $0.50. Updated November 5, 2026. A price more than 70% below list is what buyers were billed, not an error. Why so cheap?
Claude Fable 5.1 vs Inception: Mercury 2.5 — FAQ
Is Claude Fable 5.1 or Inception: Mercury 2.5 cheaper?
Inception: Mercury 2.5 is cheaper on a blended token mix, by about 93%. A request costs what its provider charged, UberLLM adds no fee, and every request is listed with its cost in Activity.
What's the price difference between Claude Fable 5.1 and Inception: Mercury 2.5?
Claude Fable 5.1: $0.5410 in / $2.70 out per 1M tokens. Inception: Mercury 2.5: $0.0460 in / $0.1725 out per 1M tokens. That's roughly a 93% blended difference. Prices are live; UberLLM adds no fee.
Can I use both Claude Fable 5.1 and Inception: Mercury 2.5 with one API?
Yes. Both are served through a single OpenAI-compatible endpoint — set the base URL to https://api.uberllm.dev/v1 and your UberLLM key, then switch between them by changing the model id. Anthropic SDKs work via https://api.uberllm.dev/v1/messages.