What Is STEAMID I/O?

Updated

STEAMID I/O is a free web-based converter and lookup tool for Steam account identifiers. It converts between steamID, steamID3, steamID64 (also called community ID or friendID), and customURL, and it can locate a user's Steam Community profile from any of those formats. Use it when you have one form of Steam ID and need another — for example, turning a customURL into the numeric steamID64 required by many APIs and third-party services.

What it does

The site's stated purpose is to "convert steamIDs, steamID64s, steamID3s, customURLs and find Steam Community profiles." In practice that means:

  • Conversion — take any supported identifier and output the others.
  • Lookup — resolve an identifier to the matching Steam Community page.
  • Single or batch — a "single entry" mode for one ID and an "extended list" mode for working through several at once.

The identifier types it handles

Identifier What it is
steamID The original unique identifier for a Steam account
steamID3 A newer format derived from the steamID
steamID64 Also called community ID or friendID; the numeric form used to reach a user's Steam Community page
customURL An optional, personalized identifier for a user's Steam Community page

The relationships matter: a steamID can be converted to a steamID3 and to a steamID64, and the steamID64 is what lets you find a user's Steam Community page. A customURL is an alternative, human-readable way to reach that same page.

When to use it

Reach for STEAMID I/O when:

  • You have a customURL but a tool or API expects a steamID64.
  • You have a steamID64 and want the underlying steamID or steamID3.
  • You need to confirm which Steam Community profile an identifier points to.
  • You're processing several IDs and want to convert them in a batch rather than one at a time.

Practical notes

  • Browser search plugin — if your browser supports OpenSearch (the site names Firefox, Chrome, and Internet Explorer 7+), you can install a search plugin for quicker lookups.
  • Third-party status — STEAMID I/O states it is not affiliated with Valve, and that all trademarks belong to their respective owners. Treat it as an independent utility.
  • Under the hood — the site credits a published algorithm (voogru on the Allied Modders forums), a steamID library (xPaw), and Valve's API as its foundations.

For anyone working with Steam data — developers, community managers, or server admins — it's a straightforward way to move between ID formats and resolve profiles without writing conversion code yourself.