AI Startup Hark Launches Handoff, Browser-Based Agent for Automated Web Tasks

Aug 5, 2026

AI startup Hark, founded by Brett Adcock, has launched Hark Handoff, a browser-based agent designed to autonomously complete web tasks like booking flights and ordering food. Hark claims Handoff achieved a record 97.7 score on the Online-Mind2Web benchmark and operates at less than one-tenth the token cost of competitors. However, critics point out that these benchmarks compare Handoff to older-generation models, and the startup has yet to disclose its underlying base model or undergo full pre-training.

Handoff browser agent launch

▪Hark Handoff is capable of navigating websites without official APIs, including Target, Walmart, OpenTable, LinkedIn, DoorDash, Uber Eats, United, Delta, and American.
▪Hark announced Hark Handoff, a browser-based computer use agent designed to autonomously complete tasks on the web on behalf of users.
▪Hark Handoff operates by spinning up a dedicated virtual computer with its own browser, file system, and terminal for each user request.

Benchmark performance claims

▪Hark claims Hark Handoff recorded a top-ever score of 97.7 on the Online-Mind2Web benchmark for web agents.
▪Hark claims Hark Handoff achieved a per-turn model latency of 0.8 seconds.

Model comparison limitations

▪On the WebTailBench v2 benchmark, GPT 5.5 scored 72.3, outperforming Hark Handoff's score of 68.6.
▪Hark's benchmark comparisons for Hark Handoff were run against older models, including GPT 5.5, GPT 5.4, Claude Opus 4.8, and Gemini 2.5 Pro, rather than current leaders like GPT-5.6 or Opus 5.

Pricing cost advantage

▪Hark Handoff is priced at $0.18 per million input tokens and $2.37 per million output tokens, compared to $5 and $30 respectively for GPT 5.5.
▪Hark claims it can serve Hark Handoff at less than one-tenth the token price of competing frontier models.

Training methodology opacity

▪Hark has not publicly specified which base model was used to build Hark Handoff, nor the mix of proprietary and open data used for training.
▪Hark Handoff is currently built on a post-trained model, with full pre-training planned for later in 2026.

Adcock promotional controversies

▪Hark founder Brett Adcock has faced skepticism over his promotional style, including past disputes regarding the scale of Figure AI's humanoid robot partnership with BMW.
▪Brett Adcock skipped a promised live demo at a tech conference and sidestepped questions about the BMW deal onstage in June 2025.