Best LLM for code review in 2026: Haiku 4.5 beats GPT-4o We tested four LLMs on six real buggy diffs: Claude Opus 4.7 swept the field, Haiku 4.5 beat GPT-4o 5-0, and GPT-4o finished with zero wins in 2026. May 18, 2026 · 7 min read code-reviewbenchmarksllm-comparison