# Best LLM for Coding > Updated Oct 20, 2026 · evidence through Oct 20, 2026. Synthesized from cited community evidence and open benchmarks, not vendor marketing. Canonical page: https://modelmatchbook.com/best/coding Claude Opus 5.5 ranks first for Coding as of October 20, 2026. It scores 64.85% ± 3.11 (95% interval) on Terminal-Bench 4.0 (#1 of 23) at max reasoning effort, using Claude Code, measuring a model-and-agent configuration on reproducible terminal tasks. Claude Sonnet 5.5 scores within two points, so read the top two as close rather than as a measured gap. Claude Sonnet 5.5 is the next-ranked alternative. It scores 91.37% on LiveBench Coding (#1 of 59), an objective evaluation of code generation and completion. [1,2] ## 1. Claude Opus 5.5 https://modelmatchbook.com/models/anthropic/claude-opus-5.5-20260921 Claude Opus 5.5 scores 64.85% ± 3.11 (95% interval) on Terminal-Bench 4.0 (#1 of 23) at max reasoning effort, using Claude Code, measuring a model-and-agent configuration on reproducible terminal tasks. **Best when:** Its strongest result for this task is on Terminal-Bench, which measures completing difficult repository and terminal tasks through an agent harness. [1] ## 2. Claude Sonnet 5.5 https://modelmatchbook.com/models/anthropic/claude-sonnet-5.5-20260928 Claude Sonnet 5.5 scores 91.37% on LiveBench Coding (#1 of 59), an objective evaluation of code generation and completion. **Best when:** Its strongest result for this task is on LiveBench Coding, which measures code generation and completion. [2] ## 3. Claude Fable 5.1 https://modelmatchbook.com/models/anthropic/claude-fable-5.1-20260831 Claude Fable 5.1 scores 86.38% on LiveBench Coding (#3 of 59), an objective evaluation of code generation and completion. **Best when:** Its strongest result for this task is on LiveBench Coding, which measures code generation and completion. [4] ## 4. Muse Wonder https://modelmatchbook.com/models/meta/muse-wonder-20261012 Ranks second in human preference for coding output quality on Design Arena while showing competitive performance on web development tasks. **Best when:** Select when human preference rankings indicate output quality, placing #2 of 117 on Design Arena coding category (Elo 1370). [5] **Watch out for:** - Expect lower web development specific performance, ranking #13 of 99 on LMArena WebDev (Elo 1652). [6] ## 5. Gemini 4 Argon https://modelmatchbook.com/models/google/gemini-4-argon-20261013 Mid-tier rankings across human preference arenas with competitive but not leading performance on coding-specific evaluations. **Best when:** Consider for general coding tasks, ranking #9 of 117 on Design Arena (Elo 1328) and #8 of 99 on LMArena WebDev (Elo 1678). [7,8] ## 6. DeepSeek V4.1 Flash 1017 https://modelmatchbook.com/models/deepseek/deepseek-v4.1-flash-20261017 DeepSeek V4.1 Flash 1017 ranks #8 of 117 on Design Arena's coding category (Elo 1333), based on blind human preference between generated coding results. **Best when:** Its strongest result for this task is on Design Arena coding, which measures coding results preferred in blind head-to-head comparisons. [3] ## 7. GPT-6.1 Sol https://modelmatchbook.com/models/openai/gpt-6.1-sol-20260929 GPT-6.1 Sol scores 58.18% ± 3.11 (95% interval) on Terminal-Bench 4.0 (#3 of 23) at max reasoning effort, using Codex, measuring a model-and-agent configuration on reproducible terminal tasks. **Best when:** Its strongest result for this task is on Terminal-Bench, which measures completing difficult repository and terminal tasks through an agent harness. [9] ## 8. GPT-6 Astra https://modelmatchbook.com/models/openai/gpt-6-astra-20260903 GPT-6 Astra ranks #2 of 99 on LMArena's WebDev coding arena (Elo 1774), a leaderboard built from blind human preference votes on coding tasks. **Best when:** Its strongest result for this task is on LMArena WebDev, which measures practical, real-world coding quality. [10] ## FAQ **What is the best model for Coding?** Claude Opus 5.5 ranks first as of October 20, 2026. Claude Opus 5.5 scores 64.85% ± 3.11 (95% interval) on Terminal-Bench 4.0 (#1 of 23) at max reasoning effort, using Claude Code, measuring a model-and-agent configuration on reproducible terminal tasks. [1] **What is the best alternative to Claude Opus 5.5?** Claude Sonnet 5.5 ranks second. Claude Sonnet 5.5 scores 91.37% on LiveBench Coding (#1 of 59), an objective evaluation of code generation and completion. [2] **Which open-weight model ranks highest for Coding?** DeepSeek V4.1 Flash 1017 is the highest-ranked open-weight model, at #6. DeepSeek V4.1 Flash 1017 ranks #8 of 117 on Design Arena's coding category (Elo 1333), based on blind human preference between generated coding results. [3] ## Sources 1. "Within the 23 catalog models matched to this evaluation: Scores 64.85% ± 3.11 (95% interval) on Terminal-Bench 4.0 (#1 of 23) at max reasoning effort, using Claude Code, measuring a model-and-agent configuration on reproducible terminal tasks." (Terminal-Bench, https://www.tbench.ai/) 2. "Within the 59 catalog models matched to this evaluation: Scores 91.37% on LiveBench Coding (#1 of 59), an objective evaluation of code generation and completion." (LiveBench Coding, https://livebench.ai/) 3. "Within the 117 catalog models matched to this evaluation: Ranks #8 of 117 on Design Arena's coding category (Elo 1333), based on blind human preference between generated coding results." (Design Arena coding, https://www.designarena.ai/) 4. "Within the 59 catalog models matched to this evaluation: Scores 86.38% on LiveBench Coding (#3 of 59), an objective evaluation of code generation and completion." (LiveBench Coding, https://livebench.ai/) 5. "Within the 117 catalog models matched to this evaluation: Ranks #2 of 117 on Design Arena's coding category (Elo 1370), based on blind human preference between generated coding results." (Design Arena coding, https://www.designarena.ai/) 6. "Within the 99 catalog models matched to this evaluation: Ranks #13 of 99 on LMArena's WebDev coding arena (Elo 1652), a leaderboard built from blind human preference votes on coding tasks." (LMArena WebDev (coding) arena, https://lmarena.ai/leaderboard) 7. "Within the 117 catalog models matched to this evaluation: Ranks #9 of 117 on Design Arena's coding category (Elo 1328), based on blind human preference between generated coding results." (Design Arena coding, https://www.designarena.ai/) 8. "Within the 99 catalog models matched to this evaluation: Ranks #8 of 99 on LMArena's WebDev coding arena (Elo 1678), a leaderboard built from blind human preference votes on coding tasks." (LMArena WebDev (coding) arena, https://lmarena.ai/leaderboard) 9. "Within the 23 catalog models matched to this evaluation: Scores 58.18% ± 3.11 (95% interval) on Terminal-Bench 4.0 (#3 of 23) at max reasoning effort, using Codex, measuring a model-and-agent configuration on reproducible terminal tasks." (Terminal-Bench, https://www.tbench.ai/) 10. "Within the 99 catalog models matched to this evaluation: Ranks #2 of 99 on LMArena's WebDev coding arena (Elo 1774), a leaderboard built from blind human preference votes on coding tasks." (LMArena WebDev (coding) arena, https://lmarena.ai/leaderboard)