---
title: Load balancing
summary: null
url: https://www.fastly.com/documentation/reference/api/load-balancing
---

Spread traffic across multiple backends automatically. See our [detailed overview of load balancing](https://www.fastly.com/documentation/learning/concepts/load-balancing/) on Fastly.

Two mechanisms exist for configuring load balancing of Fastly services via the API. _Directors_ are bound to a VCL service version and are a good choice if you want to set up load balancing as part of your version-locked service configuration, but you require more than one director group. (If you only need to put all backends under a single director consider the [`auto_loadbalance`](https://www.fastly.com/documentation/reference/api/services/backend/#field_auto_loadbalance) property of a _Backend_.)

Conversely, dynamic server pools are designed to create a load balancing container attached to your service, but with the actual servers defined dynamically. Using a dynamic server pool, servers can be added and removed without creating and activating a new version of the service.

- [Directors](https://www.fastly.com/documentation/reference/api/load-balancing/directors/)
- [Dynamic server pools](https://www.fastly.com/documentation/reference/api/load-balancing/pools/)