The year/Independent research

Paper 2508.04026

VeriWeb: Verifiable Long-Chain Web Benchmark for Agentic Information-Seeking

Published
Aug 2025
Research lab
Independent
Citations
9
GitHub
88 stars

01 In brief

Summary

VeriWeb is a new benchmark for evaluating web agents on long-horizon, information-rich tasks.

It addresses limitations of prior benchmarks that focus on single-fact retrieval and outcome-only verification.

VeriWeb emphasizes long-chain complexity (breadth- and depth-oriented search) and subtask-level verifiability, decomposing tasks into interdependent subtasks with verifiable answers.

The dataset includes 302 human-annotated tasks across five domains (scientific, finance, technology, arts, social), with an average of 4.3 subtasks and 272.5 steps per task.

Experiments with various agents (deep research, search engine, browser-use, multi-agent) show no configuration exceeds 15% success rate or 40% completion rate, highlighting significant performance gaps.

Dominant failure modes are misinformation and incomplete results.

LLM-as-a-judge evaluation shows high agreement with human scores (Pearson correlation 0.9195).

The benchmark supports fine-grained analysis of agent capabilities and failure modes, underscoring the need for more powerful agentic information-seeking capabilities.

02 From the paper

Abstract

Recent advances have showcased the extraordinary capabilities of Large Language Model (LLM) agents in tackling web-based information-seeking tasks. However, existing efforts mainly focus on single-fact retrieval and rely on outcome-only verification, thereby limiting their scalability in realistic knowledge-intensive scenarios that involve long-horizon web tasks requiring large-scale retrieval and synthesis of information from diverse sources. In this work, we introduce VeriWeb, a novel verifiable long-chain web benchmark designed to facilitate the evaluation and development of web agents within realistic web environments. Our benchmark emphasizes two critical dimensions: (1) long-chain complexity, encompassing both breadth- and depth-oriented search tasks to assess how effectively web agents ensure comprehensive information coverage and consistent context tracking in multi-hop reasoning; and (2) subtask-level verifiability, where tasks are decomposed into a sequence of interdependent verifiable subtasks. This structure enables diverse exploration strategies within each subtask, while ensuring that each subtask-level answer remains unchanged and verifiable. The benchmark consists of 302 tasks across five real-world domains, each with a complete trajectory demonstration, annotated by human experts. Extensive experiments on VeriWeb using various agents powered by different foundation models reveal significant performance gaps in handling long-horizon web tasks, highlighting the need for more powerful agentic information-seeking capabilities.