Claude Fable 5.1 vs Grok 4.6
Side-by-side comparison of API pricing, specs, benchmarks, and capabilities
| Specification |
by Anthropic
|
by xAI
|
|---|---|---|
| Overview | ||
| Status | Current flagship | Current flagship |
| Released | Sep 1, 2026 | Aug 12, 2026 |
| Pricing per million tokens | ||
| Input | $10.00/Mtok | $2.00/Mtok |
| Output | $50.00/Mtok | $6.00/Mtok |
| Blended avg | $20.00/Mtok | $3.00/Mtok |
| Cached input | $0.250/Mtok | $0.500/Mtok |
| Price basis | Cache hits and refreshes on Claude Fable 5.1 (and Claude Mythos 5.1) are priced at 0.025x the base input price — $0.25 per 1M tokens — where every other Claude model uses the standard 0.1x multiplier. Base $10/$50 per 1M tokens; Batch API $5/$25. Verified 2026-09-01 against platform.claude.com/docs/en/about-claude/pricing. | — |
| Specifications | ||
| Context window | 1M tokens | 500K tokens |
| Parameters | Proprietary | Proprietary |
| Speed (TPS) | — | — |
| Modalities | ||
| Input |
textimage
|
textimage
|
| Benchmarks sources: Vellum LLM Leaderboard / Artificial Analysis, LMSYS Chatbot Arena (UC Berkeley) | ||
| Independent composite scores measured for both models — each on its own scale | ||
| AA Intelligence Index | 65.7 | 60.9 |
| AA Agentic Index | 61.3 | 58.7 |
| AA-Omniscience Index (−100–100) | 43.5 | 30.5 |
| GDPval-AA v2 | 1853 ELO | 1729.9 ELO |
| LMSYS Chatbot Arena | — | 1461.3 ELO |
| Per-benchmark results published for Claude Fable 5.1 only — no independent per-benchmark scores exist for Grok 4.6 yet | ||
| Avg benchmark score | 54.2 | — |
| Perf / dollar | 2.7 | — |
| Terminal-Bench 2.1 | 55.8 | — |
| OSWorld-Verified | 41.7 | — |
| Humanity's Last Exam | 65 | — |
| AutoBench | 31.4 | — |
| Providers | ||
| Available from |
Anthropic — $10.00/$50.00/Mtok
|
xAI — $2.00/$6.00/Mtok
|
Cost at scale
1M tokens · 50/50 input/output| Volume | Claude Fable 5.1 | Grok 4.6 | Savings |
|---|---|---|---|
| 1M tokens | $20 | $3 | $17 (85%) |
| 10M tokens | $200 | $30 | $170 (85%) |
| 100M tokens | $2000 | $300 | $1700 (85%) |
| 1000M tokens | $20000 | $3000 | $17000 (85%) |
When to pick which
distilled from the pricing and spec data above- your workload re-reads context (agents, RAG, long chats): cached input costs $0.250/Mtok — 98% off its list input price
- you need the longer context: 1M tokens vs 500K (2×)
- cost dominates: $3.00/Mtok blended vs $20.00 — 85% less on the same 50/50 token mix
The cheaper option here — Grok 4.6 costs $3.00/Mtok blended on xAI.
Summary
Claude Fable 5.1 by Anthropic costs $10.00/Mtok input and $50.00/Mtok output, with a 1M-token context window. It supports text, image input.
Grok 4.6 by xAI costs $2.00/Mtok input and $6.00/Mtok output, with a 500K-token context window. It supports text, image input.
On a blended cost basis, Grok 4.6 is 85% cheaper than Claude Fable 5.1.
The two aren't directly comparable on average benchmark score: Claude Fable 5.1 has published per-benchmark results, while Grok 4.6 does not yet — it is measured today on independent composites (see the table above).
Note: Pricing is per million tokens. Actual costs vary with usage patterns, prompt caching, and batch discounts. Always verify against official provider pricing pages.