Most people choose a name, fall in love with it, and then discover it doesn't fit somewhere. The discovery usually comes late — after the logo, sometimes after the packaging. It is entirely avoidable, because the limits are published and they don't change often.
The caps, shortest first
These are the maximum handle lengths on the platforms worth holding. They are the same numbers this site checks against, so nothing here contradicts what a result page tells you.
- X — 15 characters
- Bluesky — 18
- Reddit — 20
- TikTok — 24
- Twitch — 25
- Instagram, Threads, YouTube, Pinterest — 30
- GitHub — 39
- Facebook — 50
X is the binding constraint and has been for years. If your handle fits in fifteen characters, length will never be the thing that stops you.
The minimums matter more than people expect
Short names fail in the other direction, and this catches people who have picked something deliberately punchy.
- Facebook needs at least 5 characters
- Twitch needs at least 4
- Reddit, YouTube, Pinterest and Bluesky need at least 3
- Instagram, Threads, X and GitHub will take 1 or 2
So a three-letter name is already locked out of Facebook and Twitch, and a two-letter name is locked out of most of the list. If you are set on something very short, decide early which platforms you are prepared to lose — or accept that you will be adding a word on some of them, which breaks the consistency you were presumably going for.
Characters are the trap, not length
Length is easy to count. What catches people is that the platforms disagree about which characters are legal, and they disagree in ways that make a separator impossible to use consistently.
- X allows letters, numbers and underscores. No dots. No hyphens.
- Instagram and TikTok allow dots and underscores.
- Reddit allows underscores and hyphens.
- GitHub allows hyphens, but not at the start or end.
- Twitch allows underscores.
Read that list again and notice there is no separator that works everywhere. A dot is illegal on X. A hyphen is illegal on Instagram and X. An underscore is the closest thing to universal and it is still not clean — and underscores are the character people most reliably forget when typing a name they heard out loud.
The rule this leaves you with
Lowercase letters and numbers, five to fifteen characters, no separators at all. That set is legal on every platform in the list, at every length in that range. Anything outside it means accepting that your handle will differ somewhere, and a handle that differs somewhere is a handle nobody can guess.
Five as the floor is Facebook's rule. Fifteen as the ceiling is X's. Between those two numbers you are free, and the freedom is worth more than the two or three extra characters you would gain by dropping a platform.
What to do with a name that doesn't fit
You have three honest options, and one bad one.
- Shorten it. Not abbreviate — shorten. A name that has been contracted into initials reads as a compromise; a genuinely shorter word doesn't.
- Drop the platform. If your audience isn't on X, X's fifteen characters are not your problem, and you can plan around thirty instead.
- Change the name. Cheaper now than after launch, and this is the moment when it is still just a candidate.
The bad option is taking a different handle on the platform that won't fit. It looks like a solution and it isn't: you now have two names, and every mention of one is a dead end for anyone looking for the other.
Run the name through a check before you commit to it. The point of doing it early is that the answer is free to act on while the name is still only an idea.