A Real-World WebAgent with Planning, Long Context Understanding, and
  Program Synthesis
Authors: name: Izzeddin Gur, name: Hiroki Furuta, name: Austin Huang, name: Mustafa Safdari, name: Yutaka Matsuo, name: Douglas Eck, name: Aleksandra Faust

Pre-trained large language models (LLMs) have recently achieved better
generalization and sample efficiency in autonomous web navigation. However, the
performance on real-world websites has still suffered from (1) open domainness,
(2) limited context length, and (3) lack of inductive bias on HTML. We
introduce WebAgent, an LLM-driven agent that can complete the tasks on real
websites following natural language instructions. WebAgent plans ahead by
decomposing instructions into canonical sub-instructions, summarizes long HTML
documents into task-relevant snippets, and acts on websites via generated
Python programs from those. We design WebAgent with Flan-U-PaLM, for grounded
code generation, and HTML-T5, new pre-trained LLMs for long HTML documents
using local and global attention mechanisms and a mixture of long-span
denoising objectives, for planning and summarization. We empirically
demonstrate that our recipe improves the success on a real website by over 50%,
and that HTML-T5 is the best model to solve HTML-based tasks; achieving 14.9%
higher success rate than prior SoTA on the MiniWoB web navigation benchmark and
better accuracy on offline task planning evaluation.