Claude Opus 4.8 (Fast) vs GLM 5.1: side-by-side summary

Claude Opus 4.8 (Fast) and GLM 5.1 are available through the OpenRouter API, so switching between them takes a model slug change rather than a new integration.

Claude Opus 4.8 (Fast), from Anthropic, has a 1,000,000-token context window and is priced at $10/M tokens input, $50/M tokens output on OpenRouter.

GLM 5.1, from Z.ai, has a 204,800-token context window and is priced at $0.896/M tokens input, $2.816/M tokens output on OpenRouter.

Context window

• Claude Opus 4.8 (Fast): 1,000,000 tokens
• GLM 5.1: 204,800 tokens

Price

• Claude Opus 4.8 (Fast): $10/M tokens input, $50/M tokens output
• GLM 5.1: $0.896/M tokens input, $2.816/M tokens output

Provided by

• Claude Opus 4.8 (Fast): Anthropic
• GLM 5.1: Z.ai

• Claude Opus 4.8 (Fast) model details, providers and pricing
• GLM 5.1 model details, providers and pricing