Last verified: August 20, 2026TL;DR: For pure coding benchmark performance, GPT-5.5 and Claude Opus 4.8 are virtually ti...

Last verified: August 20, 2026TL;DR: For pure coding benchmark performance, GPT-5.5 and Claude Opus 4.8 are virtually tied (~88.7% SWE-bench Verified). However, on the harder, contamination-resistant SWE-bench Pro benchmark, Claude Opus 4.8 leads decisively (69.2% vs 58.6% for GPT-5.5). Gemini 3.1 Pro trails in Verified (80.6%) but offers a 1M-token context window and native multimodal input, making it ideal for agentic workflows that ingest large codebases, diagrams, or video. Beyond benchmark scores, enterprises must govern AI agents like coding co-pilots to prevent data leaks and destructive actions—lessons highlighted by recent incidents involving Replit’s agent and Microsoft 365 Copilot. What to Look For in an LLM for CodingWhen evaluating LLMs for coding assistance, consider these key dimensions:Coding benchmark performance: SWE-bench Verified (human-validated Python GitHub issue repair) and the harder, contamination-resistant SWE-bench Pro (multi-language, professional repositor...