Every platform has its own rules. Here's the up-to-date 2026 reference, useful when you're trying to use the same handle everywhere.
X / Twitter — 4 to 15 characters. Letters, numbers, underscores. Cannot include the word "Twitter" or "Admin". Display name is separate and goes up to 50.
Reddit — 3 to 20 characters. Letters, numbers, underscore, dash. Once chosen, it cannot be changed (Reddit allows only username transfers via account move, not edits).
Discord — 2 to 32 characters. Lowercase only since the May 2023 username migration. Letters, numbers, period, underscore. The old discriminator system (#1234) is gone for most accounts.
Instagram — 1 to 30 characters. Letters, numbers, period, underscore. No spaces.
GitHub — 1 to 39 characters. Alphanumeric and single dashes. Cannot start or end with a dash. Cannot have two consecutive dashes.
TikTok — 2 to 24 characters. Letters, numbers, period, underscore. You can change it once every 30 days.
YouTube handle (the new @handle system) — 3 to 30 characters. Letters, numbers, period, dash, underscore. Display name and handle are separate now.
Gmail — 6 to 30 characters. Letters, numbers, periods. Periods are ignored by the routing layer (yourname@ and your.name@ go to the same inbox).
The "fits everywhere" zone: - 4 to 15 characters - only lowercase letters, numbers, and underscore - no leading number - no leading or trailing punctuation
If you want one handle across every platform listed above, those four rules cover all of them. PickName's generator filters for this band when you toggle "Cross-platform safe" mode (added April 27, 2026).