WebArena and OSWorld — web and desktop agent benchmarks WebArena web agents 812 tasks, 4 self-hosted apps shopping, forum, gitlab-like, business CMS + utilities: map, calculator, scratchpad execution-based evaluation via gym APIs release: GPT-4 agent 14.41%, human 78.24% extensions: VisualWebArena, TheAgentCompany pinned app versions reproducible scoring OSWorld desktop agents 369 tasks, Ubuntu + Windows + macOS 1920x1080 screenshots as observation keyboard + mouse control of real apps release: best model 12.24%, human 72.36% OSWorld-G: 564-sample grounding suite + Jedi training OSWorld-Human: expert gold trajectories top agents use 1.4-2.7x more steps than needed two primary failure modes 1. GUI grounding pixel to element mapping model cannot localize a button reliably; mis-clicks dominate low-level failures 2. operational knowledge which menu, which shortcut tail knowledge humans build over years; agents guess from training snapshots production fix: Claude/OpenAI CUA/Gemini computer use (Lesson 21) vision-based; trained on WebArena/OSWorld-shaped workloads; per-step safety services assess each action before execution report success rate AND trajectory efficiency (steps / gold) on every run.