BU Ultrafast is our fastest browser agent. Until Oct 30 it was behind a waitlist. Now it is on every Browser Use Cloud plan in the US, free plan included.
22 seconds, under a cent
The median task takes 22 seconds and costs $0.0064. Our default agent on GPT-6 Luna takes 79 seconds and $0.0098. That is more than 3x faster, and cheaper per task.
Source: medians of completed runs, Oct 16-29, 2026, at most 1,000 per project. Ultrafast: 12,238 runs, 134 projects. Default: 146,120 runs, 9,473 projects. In the 8 projects with 20+ runs on both, Ultrafast was faster and cheaper in all 8. Cost is the model and search charge per run; browser and proxy are billed separately.
Try it
Set model to bu-ultrafast. Nothing else changes.
curl https://api.browser-use.com/api/v4/runs \
-H "X-Browser-Use-API-Key: $BROWSER_USE_API_KEY" \
-H "Content-Type: application/json" \
-d '{"task": "Find the cheapest flight from SFO to JFK next Friday", "model": "bu-ultrafast"}'Need more reasoning per step? Use bu-fast. It is the same agent.
Pricing
bu-ultrafast runs GPT-6 Luna on OpenAI's priority tier, so tokens bill at priority rates, 2x standard. bu-fast bills at standard rates, and so does bu-ultrafast on HIPAA projects. Both work on the free plan.
If you joined the waitlist, there is nothing to do. You already have it.
Read more: BU Ultrafast, the docs, or start in Browser Use Cloud.
