Claude Fable 5 vs Grok 4.1 Fast
Pricing verdict: Claude Fable 5 vs Grok 4.1 Fast: Grok 4.1 Fast is cheaper for input-heavy usage ($0.20/M vs $10.00/M input tokens), while Grok 4.1 Fast is better for long-context tasks (2,000,000 tokens).
Direct answer: choose Grok 4.1 Fast for lower token spend and choose Grok 4.1 Fast when your workload needs longer context.
Compare API pricing, input and output token costs, context windows, and monthly estimates on one page so you can pick the right model fast.
Cost Comparison (1000 input + 500 output tokens, 100 requests/day)
Claude Fable 5
Grok 4.1 Fast
Cost Differences
Grok 4.1 Fast costs less than Claude Fable 5
Quick Recommendation
Winner for direct API pricing: Grok 4.1 Fast. At the default workload, Grok 4.1 Fast saves about $103.65/month ($1,261.075/year) versus Claude Fable 5.
Feature Comparison
| Feature | Claude Fable 5 | Grok 4.1 Fast |
|---|---|---|
| Provider | Anthropic | xAI |
| Input Price | $10.00/1M tokens | $0.20/1M tokens |
| Output Price | $50.00/1M tokens | $0.50/1M tokens |
| Context Window | 1,000,000 tokens | 2,000,000 tokens |
| Max Output | 128,000 tokens | 131,072 tokens |
| Category | flagship | efficient |
| Capabilities | textvisionreasoningcode | textreasoningcode |
| Release Date | 6/9/2026 | 1/15/2026 |
Claude Fable 5 vs Grok 4.1 Fast: Which Should You Choose?
Choosing between Claude Fable 5 and Grok 4.1 Fast depends on your priorities: cost efficiency, context length, or raw capability. Grok 4.1 Fast is the more affordable option at $0.20/1M input tokens — 98% cheaper than Claude Fable 5. Meanwhile, Grok 4.1 Fast offers a significantly larger context window at 2,000,000 tokens vs 1,000,000 for Claude Fable 5.
These models come from different providers — Anthropic and xAI — which means different API ecosystems, SDKs, rate limits, and terms of service. If you're already integrated with Anthropic, switching to xAIinvolves migration effort beyond just pricing. Factor in your existing infrastructure when deciding.
These models target different tiers: Claude Fable 5 is a flagship model while Grok 4.1 Fast is efficient. This means they're optimized for different workloads. Claude Fable 5 is built for complex tasks that require deeper reasoning, while Grok 4.1 Fast offers better value for routine operations.
Output costs matter too. Claude Fable 5 charges $50.00/1M output tokens vs $0.50 for Grok 4.1 Fast. For generation-heavy workloads (content creation, code generation, summarization), output pricing often dominates your bill. Grok 4.1 Fast has the edge here at $0.50/1M output tokens.
Multimodal capabilities: Claude Fable 5 supports vision (image inputs) while Grok 4.1 Fast is text-only. If your application needs image understanding, this narrows your choice.
Best Use Cases
Choose Claude Fable 5 when:
- • You need more capabilities (vision)
- • You're already using Anthropic's API ecosystem
Choose Grok 4.1 Fast when:
- • Budget is a primary concern
- • You need a larger context window (2,000,000 tokens)
- • You need longer outputs (up to 131,072 tokens)
- • You're already using xAI's API ecosystem
- • You're running high-volume, latency-sensitive workloads
Pros and Caveats at a Glance
Claude Fable 5
- • Input pricing: $10.00/M tokens
- • Output pricing: $50.00/M tokens
- • Context window: 1,000,000 tokens
- • Max output: 128,000 tokens
Watch out for
- • Higher input cost than Grok 4.1 Fast
- • Higher output cost than Grok 4.1 Fast
- • Smaller context window than Grok 4.1 Fast
Grok 4.1 Fast
- • Input pricing: $0.20/M tokens
- • Output pricing: $0.50/M tokens
- • Context window: 2,000,000 tokens
- • Max output: 131,072 tokens
Watch out for
- • Trade-offs are minor in this matchup.
Try Different Scenarios
Use the calculator below to see how costs change with different usage patterns
Claude Fable 5 (Anthropic)
Grok 4.1 Fast (xAI)
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Which is cheaper, Claude Fable 5 or Grok 4.1 Fast?▼
What is the context window difference between Claude Fable 5 and Grok 4.1 Fast?▼
Which model is better for AI Agent / Agentic Workflows?▼
Which model has better overall pricing for heavy usage?▼
Where can I compare Anthropic and xAI API pricing beyond this model matchup?▼
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