Claude Fable 5.1 vs Grok 4.3: Release Comparison
Comparison of the Claude Fable 5.1 and Grok 4.3 releases: 5 and 4 models respectively, each with different intelligence, performance, and pricing characteristics. Below is a comparison of the key metrics across all 9 models.
- For intelligence, Claude Fable 5.1 scores highest: Claude Fable 5.1 (Adaptive Reasoning, Max Effort, Default Fallback) at 53, against Grok 4.3 (high) at 25 for Grok 4.3.
- For output speed, Grok 4.3 is fastest: Grok 4.3 (high) at 111 t/s, against Claude Fable 5.1 (Adaptive Reasoning, Max Effort, Default Fallback) at 67 t/s for Claude Fable 5.1.
- For cost per task, Grok 4.3 is cheapest: Grok 4.3 (Non-reasoning) at $0.14, against Claude Fable 5.1 (Adaptive Reasoning, Low Effort, Default Fallback) at $2.37 for Claude Fable 5.1.
Releases compared
Intelligence
Artificial Analysis Intelligence Index
Intelligence Index vs. Cost per Intelligence Index Task
Cost
Cost per Intelligence Index Task
Speed & Latency
Output Speed
Capability Scores
Capability Indices
Incorporates 7 evaluations: AA-Omniscience, GDPval-AA v2, AA-Briefcase, Humanity's Last Exam, AutomationBench-AA, AA-LCR v1.1, GDP.pdf · Higher is better
Incorporates 6 evaluations: AA-Omniscience, GDPval-AA v2, AA-Briefcase, AutomationBench-AA, AA-LCR v1.1, GDP.pdf · Higher is better
Incorporates 7 evaluations: AA-Omniscience, GDPval-AA v2, AA-Briefcase, Humanity's Last Exam, AA-LCR v1.1, GDP.pdf, AutomationBench-AA · Higher is better
Incorporates 6 evaluations: AA-Omniscience, GDPval-AA v2, AA-Briefcase, MLCR-AA, Humanity's Last Exam, AutomationBench-AA · Higher is better
Incorporates 6 evaluations: AA-Omniscience, Humanity's Last Exam, CritPt, GDPval-AA v2, AA-Briefcase, Terminal-Bench 4.0 · Higher is better
Incorporates 5 evaluations: AA-Omniscience, Humanity's Last Exam, GDPval-AA v2, AA-Briefcase, AA-LCR v1.1 · Higher is better
Further details
Input modality | Output modality | Weights | Provider Benchmarks | ||||||||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Claude Fable 5.1 (Adaptive Reasoning, Max Effort, Default Fallback) |  Anthropic | 53 | 57 | 60 | 61 | 58 | 57 | 63 | $7.63 | $7.2 | $10.00 | $50.00 | $0.25 | $13,129 | 78k | 47k | 188M | 67 | 213.23s | 213.23s | 220.72s | 749.10s | - | 1M | Sep 2026 | - | Yes | Supports: text and image | Supports: text | Not available | - | | |
| Claude Fable 5.1 (Adaptive Reasoning, Xhigh Effort, Default Fallback) | Anthropic | 53 | 56 | 58 | 61 | - | 57 | 62 | $5.98 | $7.2 | $10.00 | $50.00 | $0.25 | $9,063 | 61k | 34k | 121M | 61 | 91.63s | 91.63s | 99.81s | 632.63s | - | 1M | Sep 2026 | - | Yes | Supports: text and image | Supports: text | Not available | - | | |
| Claude Fable 5.1 (Adaptive Reasoning, High Effort, Default Fallback) | Anthropic | 51 | 54 | 56 | 58 | - | 55 | 60 | $3.91 | $7.2 | $10.00 | $50.00 | $0.25 | $5,242 | 38k | 19k | 62M | 51 | 12.45s | 12.45s | 22.32s | 469.10s | - | 1M | Sep 2026 | - | Yes | Supports: text and image | Supports: text | Not available | - | | |
| Claude Fable 5.1 (Adaptive Reasoning, Medium Effort, Default Fallback) | Anthropic | 49 | 52 | 54 | 57 | - | 52 | 58 | $2.98 | $7.2 | $10.00 | $50.00 | $0.25 | $3,983 | 28k | 12k | 44M | 51 | 7.47s | 7.47s | 17.31s | 333.43s | - | 1M | Sep 2026 | - | Yes | Supports: text and image | Supports: text | Not available | - | | |
| Claude Fable 5.1 (Adaptive Reasoning, Low Effort, Default Fallback) | Anthropic | 47 | 49 | 52 | 54 | - | 49 | 55 | $2.37 | $7.2 | $10.00 | $50.00 | $0.25 | $3,158 | 22k | 8k | 33M | 50 | 5.23s | 5.23s | 15.15s | 280.39s | - | 1M | Sep 2026 | - | Yes | Supports: text and image | Supports: text | Not available | - | | |
| Grok 4.3 (high) |  SpaceXAI | 25 | 28 | 18 | 33 | 27 | 31 | 41 | $0.17 | $0.6 | $1.25 | $2.50 | $0.20 | $332 | 18k | 11k | 87M | 111 | 19.61s | 19.61s | 24.11s | 161.88s | - | 1M | Apr 2026 | - | Yes | Supports: text and image | Supports: text | Not available | - |   | |
| Grok 4.3 (medium) | SpaceXAI | 25 | - | - | - | - | - | - | - | $0.6 | $1.25 | $2.50 | $0.20 | - | - | - | - | 108 | 11.48s | 11.48s | 16.12s | - | - | 1M | Apr 2026 | - | Yes | Supports: text and image | Supports: text | Not available | - | | |
| Grok 4.3 (low) | SpaceXAI | 24 | - | - | - | - | - | - | - | $0.6 | $1.25 | $2.50 | $0.20 | - | - | - | - | 102 | 4.55s | 4.55s | 9.43s | - | - | 1M | Apr 2026 | - | Yes | Supports: text and image | Supports: text | Not available | - | | |
| Grok 4.3 (Non-reasoning) | SpaceXAI | 15 | 16 | 14 | 19 | - | 15 | 21 | $0.14 | $0.6 | $1.25 | $2.50 | $0.20 | $203 | 9k | 0 | 12M | 109 | 0.70s | 0.70s | 5.29s | 86.37s | - | 1M | Apr 2026 | - | No | Supports: text and image | Supports: text | Not available | - | | |