WebBrain: open-source local browser agent with a 450M browser-specialized VLM

ButtercupLyn100 · reddit · 2026-09-29

A developer open-sourced WebBrain, an agent that lets LLMs see and operate a browser, deliberately avoiding dependence on a single cloud provider: it works with local models via LM Studio/Ollama as well as cloud APIs.

The standout is a small vision model webbrain-vl-2-450M, based on LFM-2.5-VL-450M and fine-tuned on browser screenshots/tasks — so browser perception can run locally on a tiny model via WebGPU instead of sending every screenshot to a giant multimodal model.

Architecture: screenshot + browser accessibility tree for perception (not pure DOM parsing), a browser-specialized tiny VLM, a model-agnostic planner, Chrome/Edge/Firefox/Chromium support, optional cloud execution, fully open source. The author wants to explore how far browser agents can go with small local models, and asks which model people would try as the planner.

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