Load Balancers

The Cloud Subscription plans and Dedicated plans have load balancing mechanisms built-in. This documentation will provide further information on how they work on each plan.

If you're looking for instructions on how to construct connection URLs and include your API token, see Connection URLs.

How Browserless Routing Works

This diagram shows the typical flow: your application sends requests to a regional endpoint, which routes through that region's load balancer to a Browserless instance in our fleet.

Cloud subscriptions' load balancing

When you fire a request to our endpoints, it will go through our load balancers and will be sent to one of our instances to be handled. These are the cloud subscription endpoints available:

1. SFO endpoint: https://production-sfo.browserless.io
2. LON endpoint: https://production-lon.browserless.io
3. AMS endpoint: https://production-ams.browserless.io

Choosing the right region greatly improves performance by reducing latency and ensuring your requests are handled by the closest available instance.

We list our shared fleet's IP addresses for whitelisting purposes.

Our cloud-unit fleet is comprised of many machines running browserless, and our load-balancer will automatically determine which machine to handle the request. If, say, a machine is too overloaded to handle the inbound connection then our load-balancer routes the request to another. In very plain terms we use a modified least-connected algorithm to ensure your request is handled appropriately.

See Also

Connection URLs — step-by-step instructions on building the connection string you need based on your library, preferred regions, flags and token.