Polarison

Claude Fable 5.1 vs Grok 4.7: pricing and benchmarks

Grok 4.7 is 80% cheaper on input tokens ($2.00 vs $10.00 per 1M). Grok 4.7 is 88% cheaper on output tokens ($6.00 vs $50.00 per 1M). On our document Q&A workload (50,000 questions a month), Grok 4.7 costs $980.00 a month versus $5,500 for Claude Fable 5.1, 82% less. Epoch AI has not published a capability index score for Grok 4.7 yet.

Prices verified September 26, 2026.

Which should you choose?

Overall capability
Too close to call

Epoch AI has not published a capability index score for Grok 4.7 yet.

Price
Grok 4.7

Grok 4.7 costs $3.00 per 1M tokens (3:1 input-to-output mix) vs $20.00 for Claude Fable 5.1, 85% less.

Pricing and specs

Claude Fable 5.1Grok 4.7
ProviderAnthropicxAI
API model IDclaude-fable-5-1grok-4.7
Input / 1M tokens$10.00$2.00
Cached input / 1M tokens$0.25$0.50
Output / 1M tokens$50.00$6.00
Long-context rates—$4.00 in / $12.00 out above 200K prompt tokens
Context window1M tokens500K tokens
Max output128K tokens—
Batch discount50% off—

Benchmarks

Claude Fable 5.1Grok 4.7
Epoch Capabilities Index164.5—
GPQA Diamond· Science reasoning——
FrontierMath (Tiers 1–3)· Advanced math90.2%—
SimpleQA Verified· Factual accuracy70.8%—
ARC-AGI-2· Abstract reasoning90.0%—
DeepSWE· Coding——
APEX-Agents· Agentic work47.4%—

Source: Epoch AI, best recorded result per model (CC BY 4.0). A dash means no published score. See all benchmarks

Monthly cost for real workloads

WorkloadClaude Fable 5.1Grok 4.7Difference
Support chatbot
100,000 replies a month, ~1,500 input tokens (system prompt + history) and ~400 output tokens each.
$3,500$540.00Grok 4.7 85% cheaper
Document Q&A (RAG)
50,000 questions a month with ~8,000 tokens of retrieved context and ~600 output tokens each.
$5,500$980.00Grok 4.7 82% cheaper
Coding agent
10,000 agent steps a month, ~40,000 input tokens each (70% read from the prompt cache) and ~2,000 output tokens.
$2,270$500.00Grok 4.7 78% cheaper

Estimates use standard list prices and ignore cache-write surcharges. Different tokenizers can count the same text differently, so test with your own prompts.

Claude Fable 5.1 vs Grok 4.7 cost calculator

Standard-tier list prices. Long-context rates apply automatically where the provider publishes a threshold. Excludes cache-write surcharges, taxes, batch and volume discounts.

Claude Fable 5.1 pricing notes

Anthropic’s model for demanding reasoning and long-horizon agentic work.

  • Cache hits cost 2.5% of the base input price, versus 10% on other Claude models.
  • Cache writes cost $12.50 (5-minute cache) or $20 (1-hour cache) per 1M tokens.
  • Uses Anthropic’s newer tokenizer, which produces roughly 30% more tokens for the same text.
  • US-only inference (inference_geo: "us") costs 1.1x.
Anthropic official pricing ↗

Grok 4.7 pricing notes

xAI’s newest flagship for coding and general use, with agentic tool calling and configurable reasoning.

  • Requests with 200K or more prompt tokens are billed at $4 input / $1 cached / $12 output for all tokens.
  • Web Search costs $5 per 1,000 calls; X Search is billed per item fetched, at $5 per 1,000 posts and $10 per 1,000 user profiles.
xAI official pricing ↗

Frequently asked questions

Is Claude Fable 5.1 cheaper than Grok 4.7?
Grok 4.7 is 80% cheaper on input tokens ($2.00 vs $10.00 per 1M). Grok 4.7 is 88% cheaper on output tokens ($6.00 vs $50.00 per 1M). On our document Q&A workload (50,000 questions a month), Grok 4.7 costs $980.00 a month versus $5,500 for Claude Fable 5.1, 82% less.
Which is more capable, Claude Fable 5.1 or Grok 4.7?
Epoch AI has not published a capability index score for Grok 4.7 yet.
How much does Claude Fable 5.1 cost per 1M tokens?
Claude Fable 5.1 costs $10.00 per 1M input tokens and $50.00 per 1M output tokens, and $0.25 per 1M cached input tokens on Anthropic’s standard tier.
How much does Grok 4.7 cost per 1M tokens?
Grok 4.7 costs $2.00 per 1M input tokens and $6.00 per 1M output tokens, and $0.50 per 1M cached input tokens on xAI’s standard tier.
Which has the larger context window, Claude Fable 5.1 or Grok 4.7?
Claude Fable 5.1 has the larger context window: 1M tokens versus 500K for Grok 4.7.

Related comparisons