---
license: mit
task_categories: [image-to-text]
tags: [web-agents, world-models, webarena]
---
# browser-world-models: WebArena reddit transitions

Browser state transitions collected by running the **106 official WebArena reddit tasks**
against a self-hosted, reproducible WebArena (Postmill) instance (rootless Apptainer on
SLURM). Each row: before/after screenshots, the Set-of-Marks action between them, the task
goal, and LLM-judge next-state labels in two target formats (free prose and a fixed
CHANGED/NAV/CONTENT/UI/ERROR template).

- ~726 transitions / 110 trajectories / 1 site (Postmill "reddit"), no-op rate ~0.49
- Labels: gpt-4o-mini judge from (before, action, after); simulator trains on (before, action) -> label
- Pipeline + training/eval code: https://github.com/photomz/browser-world-models (PR #4)
- Companion pilot set (live web, 44 sites): sudac/browser-world-models-transitions

Collected 2026-06-10. Single-site reproducible complement to the live-web pilot set.