modelgrep

Anthropic: Claude Opus 4.8 vs Z.ai: GLM 5.1

anthropic logoAnthropic: Claude Opus 4.8anthropic/claude-opus-4.8VSz-ai logoZ.ai: GLM 5.1z-ai/glm-5.1

Anthropic: Claude Opus 4.8 wins on more metrics (5 of 9), but the right pick depends on what you optimize for — see the breakdown below.

MetricAnthropic: Claude Opus 4.8Z.ai: GLM 5.1
Intelligence Index55.7✓40.2
Coding Index74.3✓55.8
GPQA Diamond92%✓87%
Design Arena Elo1288✓—
Speed (tokens/sec)72101✓
Latency1.8s304ms✓
Input price /M$5.00$0.966✓
Output price /M$25.00$3.04✓
Context window1M✓203K
CapabilitiesReasoningToolsJSONVisionReasoningToolsJSON
Anthropic: Claude Opus 4.8 details →Z.ai: GLM 5.1 details →