Grok 4.1 Fast vs Seed 2.0 Pro

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.

ByteDance

Seed 2.0 Pro is ByteDance's flagship general-purpose model, released in February 2026 under the Doubao brand through the Volcengine API platform, developed by the company's Seed research team as a foundation for agentic applications requiring long-horizon reasoning and multimodal input comprehension. The model accepts text, images, and extended video — including hour-length recordings — targeting enterprise use cases in long-form document analysis, agentic coding (integrated with ByteDance's TRAE IDE), and multi-turn reasoning tasks. It anchors a three-tier product family alongside Seed 2.0 Lite and Mini, positioned as ByteDance's response to frontier model competition in the Chinese and global enterprise AI markets.