2 models
Ranked by IFBench
Reasoning Tools Open weights 81.7

Largest Nemotron 3 model for maximum open-weight reasoning and agent accuracy

nvidia/nemotron-3-ultra-550b-a55b 2026-06-04 1M context $0.5/M input $2.5/M output
15 providers
Reasoning Tools JSON 81.0

xAI's default Grok for chat, coding, agentic tools, and lower hallucination risk

xai/grok-4.3 2026-04-17 1M context $1.25/M input $2.5/M output
28 providers