---
header: WebSockets
lang: en
last_updated: '2025-12-16'
url: https://docs.fastly.com/products/websockets
---

Fastly supports the use of the [WebSocket protocol](https://datatracker.ietf.org/doc/html/rfc6455). This protocol allows you to establish long-lived, two-way, interactive communication sessions between an end user's client (such as a web browser) and your servers.

## Limitations and considerations

Keep in mind the following limitations and considerations:

- WebSockets is not compatible with [shielding](https://www.fastly.com/documentation/guides/getting-started/hosts/shielding) or the [Fastly Next-Gen WAF](https://docs.fastly.com/products/fastly-next-gen-waf).
- When [adding a host](https://www.fastly.com/documentation/guides/getting-started/hosts/working-with-hosts) to your Fastly service configuration, only the **Name**, **Address**, **Enable TLS**, and **Override Host** origin server settings are supported with WebSockets.
- When handling a WebSocket request, `vcl_log` will run at the time the request is accepted rather than when the connection ends.
- Client request headers that are added, removed, or modified on your `Request` (or `req.http` in VCL) will be reflected in the WebSocket handoff.
- If you have TLS certificates on your origin server, they must be signed by a public certification authority. Self-signed TLS certificates are not supported.

## Billing

> **NOTE:** Billing limits for this product may be different depending on your [account type](https://www.fastly.com/documentation/guides/account-info/billing/account-types/), if you've purchased a [packaged offering](https://www.fastly.com/package-entitlements/), or are using a [product or feature trial](https://www.fastly.com/documentation/guides/account-info/billing/about-the-products-page).

Use of the WebSocket protocol is disabled by default. Users assigned the superuser role in eligible accounts can enable it on the [Products](https://manage.fastly.com/products) page. Once enabled, any user on your account with the [appropriate permissions](https://www.fastly.com/documentation/guides/account-info/user-access-and-control/configuring-user-roles-and-permissions) will be able to use this communications protocol.

Enabling WebSockets on your account will also result in changes to your monthly bill. We base billing for WebSockets on a combination of bandwidth and connection time. Connection time is measured for each connection in usage minutes (rounded up to whole minutes) and aggregated monthly to millions of minutes. Bandwidth is included as part of your overall delivery bandwidth rate in your monthly billing statement.

> **NOTE:** For more details about this product, including [pricing information](https://www.fastly.com/pricing) and help with purchasing it, contact your account manager or email [sales@fastly.com](mailto:sales@fastly.com).