Devstral-2-123B vs Seed 2.0 Pro

Devstral-2-123B

Mistral AI

Devstral 2, released by Mistral AI on December 9, 2025, is a 123 billion parameter dense transformer model specifically designed for software engineering tasks. It features a 256K token context window and achieved 72.2% on SWE-bench Verified at release, making it a competitive open-weight option for automated coding and agentic development. Devstral 2 targets code generation, multi-file software engineering, and agentic development workflows under a modified MIT license.

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.