Browser Run just got a major upgrade. By rebuilding on top of Cloudflare’s own Containers, we’ve unlocked higher usage limits, faster performance, and better reliability — all without requiring any changes from you. Here’s what’s new and how we made it happen.
What’s New in Browser Run
Starting today, you can spin up 60 browsers per minute via the Workers binding and run up to 120 concurrent browsers — that’s 4x the previous limit. Meanwhile, Quick Action response times have dropped by more than 50%. These improvements are live now and require no action on your part. Beyond raw numbers, we’re also shipping fixes and new features faster than before.
Understanding Browser Run
For those new to it, Browser Run lets developers programmatically control and interact with headless browser instances running on Cloudflare’s global network. This capability powers a range of use cases:
- End-to-end testing of web applications
- Secure investigation of suspicious URLs
- Rendering PDF documents with ease
- Quick actions like capturing screenshots or extracting content
More recently, Browser Run has become a critical enabler for AI agents that need to interact with the web. Our goal is to make it the go-to platform for responsibly using automated browsers at massive scale.
The Migration: From Shared Infrastructure to Dedicated Containers
Previously, Browser Run shared infrastructure with Browser Isolation (BISO). While technically similar, this arrangement presented several challenges:
- Slower startup times due to BISO’s larger container images
- Suboptimal global distribution, which hurt resiliency and latency
- Scaling bottlenecks from mixing BISO’s long, steady sessions with Browser Run’s short, spiky usage
Fortunately, Cloudflare released Durable Object (DO)-enabled Containers in open beta last year. We adopted them early, which allowed us to build on our own platform — experiencing and fixing pain points before external customers do.
A Gradual, Safe Rollout
We began by inserting a Worker in our incoming request paths to serve some users from Containers while others remained on BISO. This dual support let us compare performance, isolate bugs, and build confidence. We then ramped up in stages:
- First, all Quick Actions endpoints moved to Containers
- Next, Workers browser binding connections for free accounts
- Then pay-as-you-go accounts for further validation
- Finally, all contract customers — with zero disruption
Throughout, customers needed no changes to their existing Workers or code.
Performance Data and Results
The numbers speak for themselves. The Container-based architecture delivers:
- 4x higher concurrency (120 browsers vs. 30 previously)
- 50%+ faster Quick Action response times
- Improved global distribution, reducing latency worldwide
These gains come from isolating Browser Run’s workloads and optimizing startup times. Additionally, the new infrastructure enables us to ship fixes and features faster, because we no longer have to coordinate with BISO’s release cycle.
What’s Next for Browser Run
With Containers as the foundation, we’re planning even more enhancements. Expect continued improvements in scalability, reliability, and developer experience. As always, we’ll keep iterating based on your feedback. To learn more, check out our official documentation or dive into the technical details behind the migration.