modelgrep

Anthropic: Claude Fable 5 vs xAI: Grok 4.5

anthropic logoAnthropic: Claude Fable 5anthropic/claude-fable-5VSx-ai logoxAI: Grok 4.5x-ai/grok-4.5

xAI: Grok 4.5 wins on more metrics (5 of 9), but the right pick depends on what you optimize for — see the breakdown below.

MetricAnthropic: Claude Fable 5xAI: Grok 4.5
Intelligence Index59.9✓53.8
Coding Index76.5✓72.4
GPQA Diamond93%93%✓
Design Arena Elo1378✓—
Speed (tokens/sec)4674✓
Latency3.3s655ms✓
Input price /M$10.00$2.00✓
Output price /M$50.00$6.00✓
Context window1M✓500K
CapabilitiesReasoningToolsJSONVisionReasoningToolsJSONVision
Anthropic: Claude Fable 5 details →xAI: Grok 4.5 details →