What Is the Difference Between steamID, steamID3, steamID64, and customURL?

Updated

Steam uses several identifiers for the same account, and they are not interchangeable. A steamID is the original unique identifier for a Steam account; it can be converted into the newer steamID3 and steamID64 (also called community ID or friendID), and a customURL is an optional, more personalized identifier used to reach a user's Steam Community page. If you have one format and need another, a converter such as STEAMID I/O takes the value you enter and returns the matching formats so you can locate the profile.

The four identifiers at a glance

Identifier What it is Typical use
steamID The original unique identifier for a Steam account Legacy references and older tools
steamID3 A newer format derived from the steamID Modern APIs and community tools
steamID64 Also called community ID or friendID; derived from the steamID Finding a user's Steam Community page
customURL An optional, personalized identifier a user can set Looking up a Steam Community page by a readable name

Why the same account has multiple IDs

Each format exists because different systems and eras of Steam needed different representations of the same account. The steamID came first, and steamID3 and steamID64 are newer forms converted from it. Because a steamID64 lets you find a user's Steam Community page, conversion is often the practical step between "I have this number" and "I can open this profile." A customURL serves a similar lookup purpose but is chosen by the user rather than assigned, so it is only available if that person set one.

When you need a conversion

You need to convert when the identifier you hold does not match the system you are using. For example, if a tool or community page expects a steamID64 but you only have a steamID, the steamID must be converted first. Likewise, a customURL is useful for reading or sharing a profile link, but it is not the same value as the numeric IDs and cannot substitute for them.

STEAMID I/O describes itself as a steamID converter that handles steamIDs, steamID64s, steamID3s, and customURLs, and that can find Steam Community profiles. It also offers a single-entry and an extended-list lookup mode, plus an OpenSearch browser plugin for Firefox, Chrome, and Internet Explorer 7 and above, so you can run lookups from the browser search bar. The site states it is powered by Steam and is not affiliated with Valve.

Practical notes

  • Conversion is one-directional in practice: numeric IDs convert into each other, while a customURL only resolves to a profile if the user created one.
  • A steamID64 is the value most often needed to open a Steam Community page, which is why it is frequently the target of a conversion.
  • If you plan to look up many accounts, the extended-list mode is the relevant option rather than single entry.