Anthropic
Claude Sonnet 5
Claude Sonnet 5 is an AI model released by Anthropic on Tuesday, Jun 30 2026, 21 days after Claude Fable 5. Benchmark results (shown below) cover BullshitBench v2, SWE-Bench Pro, CursorBench v3.1, Terminal-Bench 2.1, BrowseComp, Humanity's Last Exam, and 3 more.
Benchmarks
Nonsense detection
BullshitBench v2Given a confidently-worded but nonsensical prompt, does the AI spot that it makes no sense and push back — instead of playing along and inventing an answer? The score is how often it clearly called out the nonsense. Higher is better.
80%-11%vs Claude Sonnet 4.6
Agentic coding
SWE-Bench ProCan the AI fix real bugs in real software? It's handed actual problems from open-source projects and has to write code that genuinely solves them. Higher is better.
63.2%
Agentic coding
CursorBench v3.1Cursor's own test of harder, real-world coding tasks inside a code editor. Higher is better.
61.2%+12.2%vs Claude Sonnet 4.6
Agentic terminal coding
Terminal-Bench 2.1Can the AI work in a command-line terminal — running commands and finishing technical setup tasks the way a developer would? Higher is better.
80.4%
Web browsing
BrowseCompCan the AI browse the web and track down hard-to-find answers? Higher is better.
84.7%
Multidisciplinary reasoning
Humanity's Last ExamHumanity's Last Exam — extremely hard expert questions across many subjects, written so you can't just look up the answer. “No tools” means the AI answers on its own. Higher is better.
43.2%+10%vs Claude Sonnet 4.6
no tools
57.4%
with tools
Agentic computer use
OSWorld-VerifiedCan the AI actually operate a computer — clicking, typing, and using real apps — to finish tasks on its own? Higher is better.
81.2%+8.7%vs Claude Sonnet 4.6
Knowledge work
GDPval-AAMeasures how well the AI does economically valuable knowledge work, judged against human experts. Shown as a rating (like a chess Elo) — higher is better.
1618-58vs Claude Sonnet 4.6
Community preference (code)
Arena Elo (Code)Like the text arena, but people vote on which AI writes better code. The votes become a chess-style Elo rating on arena.ai. Higher is better.
1543+22vs Claude Sonnet 4.6
Compare Claude Sonnet 5 with
Claude Sonnet 5 vs Claude Fable 5Claude Sonnet 5 vs GPT-5.6 SolClaude Sonnet 5 vs Gemini 3.5 FlashClaude Sonnet 5 vs Muse Spark 1.1Claude Sonnet 5 vs Grok 4.5Claude Sonnet 5 vs DeepSeek-V4-ProClaude Sonnet 5 vs Mistral Medium 3.5Claude Sonnet 5 vs Kimi K3Claude Sonnet 5 vs Composer 2.5Claude Sonnet 5 vs GLM-5.2