10 karma · joined September 8, 2020
Over the last 2 years, we observed computer use models improving at a rapid pace and saturating benchmarks. This new benchmark replaces Online-Mind2Web with our own Browserbase Benchmark v2 that better represents the complex tasks that browser agents face in the real world. It runs against 23 models (frontier and open-weight) and 9 harnesses (Claude Code to LangChain Deep Agents) on accuracy, speed, and cost.
This new benchmark confirmed our belief that the choice of an harness is becoming as important as the choice of a model. For example: claude-opus-5 runs 74% at $1.50/task on LangChain deep agents but 71% at ~$10/task on fx.
The eval harness is a CLI you can run yourself (pick harness + tools/mcps + model, pass high-level tasks, grades with LLM verifiers, has trials/concurrency/OTEL tracing): https://github.com/browserbase/stagehand/tree/main/packages/...
Happy to get into methodology, and if you want your model or harness added, just let me know.
On the act/extract/observe evals it shows promising results being extremely efficient
- act: 4.3x faster, 97% fewer LLM calls. Pass rate: 97.5% -> 98.3%. - heldout: 4.1x faster, 78% fewer LLM calls. Pass rate: 87.5% -> 97.5%. - observe: 11.1x faster, 69% fewer LLM calls. Pass rate: 75.0% -> 83.3%. - extract: 8.7x faster, 75% fewer LLM calls. Pass rate unchanged at 92%.
cost effectively 0
are you looking for a solution to go from these CUA actions to deterministic scripts? check out https://docs.stagehand.dev/v3/best-practices/caching