Head-to-head · Anthropic vs xAI
Claude Fable 5.1 vs Grok 4.7
Quick answer: Claude Fable 5.1 stands out for highest quality ceiling in the generally available Claude lineup. Grok 4.7 stands out for large context window at a moderate price. Reviewed September 2026.
Overview
Claude Fable 5.1: Claude Fable 5.1 is Anthropic's premium generally available model, priced above Opus and built for the hardest reasoning, coding and analysis tasks. Anthropic says the cheaper Opus 5.5 now matches it on most work, so Fable 5.1 makes most sense where the last few points of quality justify the price.
Grok 4.7: Grok 4.7 is xAI's latest flagship model for coding, agentic tasks and knowledge work. It has a 500,000-token context window, accepts text and image input, and supports adjustable reasoning levels.
At a glance
| Dimension | Claude Fable 5.1 | Grok 4.7 |
|---|---|---|
| Vendor | Anthropic | xAI |
| Starting price | API: $10 in / $50 out per M tokens | API: $2 to $4 in / $6 to $12 out per M tokens |
| Pricing model | Paid | Paid |
| Free tier | No | No |
| Category | Generative AI | Generative AI |
Strengths and limits
Claude Fable 5.1
- Highest quality ceiling in the generally available Claude lineup
- Suited to long, high-stakes analysis
- Heavy prompt caching lowers cost for repeated context
Watch out for
- $10 input and $50 output per million tokens
- Opus 5.5 is comparable on most tasks at lower cost
- Not needed for routine work
Grok 4.7
- Large context window at a moderate price
- Strong on coding and agent tasks
- Real-time knowledge through the xAI ecosystem
Watch out for
- Smaller enterprise ecosystem than OpenAI, Anthropic or Google
- Price steps up for prompts over 200,000 tokens
- Fewer professional integrations
Key features
Claude Fable 5.1
- 1M-token context window at standard pricing
- Top-tier reasoning and agentic performance
- Cache reads priced at a steep discount for repeated context
- Tool use and computer use
- Available through the Claude API and major clouds
Grok 4.7
- 500,000-token context window
- Text and image input
- Flexible reasoning levels
- Available through the xAI API
Pricing compared
Claude Fable 5.1 is priced by usage rather than by seat: API: $10 in / $50 out per M tokens. That means cost scales with how much text you send and receive, so estimate your monthly volume before committing.
Grok 4.7 is priced by usage rather than by seat: API: $2 to $4 in / $6 to $12 out per M tokens. That means cost scales with how much text you send and receive, so estimate your monthly volume before committing.
Frequently asked questions
Which is better, Claude Fable 5.1 or Grok 4.7?
It depends on the work. Claude Fable 5.1 stands out for highest quality ceiling in the generally available Claude lineup. Grok 4.7 stands out for large context window at a moderate price.
How do Claude Fable 5.1 and Grok 4.7 compare on price?
Claude Fable 5.1 is priced by usage rather than by seat: API: $10 in / $50 out per M tokens. That means cost scales with how much text you send and receive, so estimate your monthly volume before committing. Grok 4.7 is priced by usage rather than by seat: API: $2 to $4 in / $6 to $12 out per M tokens. That means cost scales with how much text you send and receive, so estimate your monthly volume before committing.
Is there a free option between Claude Fable 5.1 and Grok 4.7?
Neither lists a permanent free tier. Look for trials or usage-based pricing to test on real work first.