Claude Haiku 4.5 vs Grok 4.1 Fast

Claude Haiku 4.5

Anthropic

Claude Haiku 4.5, released by Anthropic in October 2025, is a fast, efficient large language model from the Claude 4.5 family optimized for high-throughput, low-latency workloads. It features a 200K token context window, 64K maximum output tokens, native image understanding, and extended thinking capabilities. Haiku 4.5 targets latency-sensitive applications such as real-time assistants, document classification, and lightweight agentic tasks where rapid response times are a primary requirement.

Grok 4.1 Fast

xAI

Grok 4.1 Fast, released by xAI in November 2025, is a fast-response variant from the Grok 4 family featuring a 2M token context window designed for high-throughput applications. It omits thinking tokens for immediate responses, reducing latency while maintaining strong output quality. Grok 4.1 Fast targets production APIs, real-time assistants, and cost-sensitive applications requiring long-context understanding at high volume.