Web agents typically observe web pages at the granularity of individual elements (buttons, links, etc.), which forces them to infer functional organization at every step. The authors propose Region4Web, which groups elements into functional regions (parts of the page serving distinct purposes) and presents these as a compact "digest" that persists across reasoning steps. On WebArena, this region-level observation reduces input length and improves task success across different LLMs and agent architectures, regardless of model size.
Main takeaways:
- Current web agents observe pages at element-level granularity, leaving functional structure implicit
- Grouping elements into functional regions (e.g., navigation bar, search box, content area) gives agents a better basis for understanding page state
- PageDigest delivers this as a persistent per-page summary rather than re-processing elements every step
- Shorter observations and higher success rates across LLM backbones on WebArena benchmark