Best LLMs for coding in 2026 ranked by 5 developer tasks. Claude Opus 4.8 leads SWE-bench Pro at 69.2%. Open-weight now at 80.6%.
DeepSeek V4 Pro scores 80.6% on SWE-bench, verified at $0.87 per million output tokens, versus GPT-5.6 Sol’s $30 and 91.9% Terminal-Bench score.