Dedicated IP vs SNI
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When a server hosts multiple HTTPS websites, it needs to know which SSL certificate to present to an incoming connection — and it needs to make that decision before the TLS handshake is complete, at which point it does not yet know which domain the client is requesting. There are two ways to solve this: assigning a dedicated IP address to each site, or using SNI (Server Name Indication), a TLS extension that lets the client identify itself first.
Dedicated IP
With a dedicated IP approach, each domain hosted on the server gets its own unique IP address. When a connection comes in, the server identifies the destination by IP and serves the corresponding SSL certificate — no additional negotiation needed.
The main advantage is universal compatibility: dedicated IP works with every client, including very old browsers and operating systems that do not support modern TLS extensions. It is also the required approach for services that are accessed by IP address directly rather than by domain name.
The downside is cost and resource usage. IPv4 addresses are a limited resource, and most hosting providers charge extra for each additional dedicated IP. For servers hosting many sites, this adds up quickly and is rarely justified by actual technical need today.
SNI — Server Name Indication
SNI is an extension to the TLS protocol that allows the client to include the hostname it is connecting to at the very start of the handshake, before any certificate is exchanged. This gives the server the information it needs to select and present the correct SSL certificate — even when multiple domains share a single IP address.
SNI has been the standard in web hosting for well over a decade and is supported by all modern browsers, operating systems, and server platforms. It eliminates the need for additional IP addresses, reduces hosting costs, and works seamlessly in virtually all real-world environments.
⚠ Note: SNI is not supported on Windows XP with Internet Explorer 8 or earlier, and some very old Android and Java environments. If your server must reliably serve clients running these legacy systems, a dedicated IP is the only option. For all other cases, SNI is sufficient.
When to Use Which
For the vast majority of use cases, SNI is the right choice. It is cost-effective, widely supported, and requires no additional IP resources. Most modern hosting control panels (cPanel, Plesk, and others) enable SNI by default, so in practice, no special configuration is needed.
A dedicated IP is worth considering only if you have a specific reason: you need to support legacy clients that predate SNI support, your service is accessed directly by IP address, or your environment has compliance or infrastructure requirements that mandate it. Outside of these cases, the extra cost of a dedicated IP offers no practical benefit.
✔ Tip: If you are unsure whether SNI is enabled on your server, contact your hosting provider — they can confirm your configuration and assist with any necessary setup.
