How to Check If a Startup Name Is Available: Domains, Social Media Handles, and Username Rules by Platform

You finally found a name that you like for your startup. Congrats! Now the bad news: you may not be able to use it as it is.

Checking if a startup name is available means checking two things before anything else: the domain, and the social media handles. Most founders check the first one carefully and the second one in a hurry.

You checked the .com. You searched X. It looked clear, so you told a few people.

Then you tried to claim the handle everywhere else.

On Instagram, garage.exit and garageexit are two different accounts. On X, the period is not allowed at all, so garage.exit is not even a valid handle. As a domain it becomes garage-exit.com. On PyPI, garage.exit, garage_exit, and garage-exit are treated as the same package.

Your name is one word in your head. Across the internet it is ten slightly different strings: a domain, a handle on every social media platform, and a name in every developer registry, each with its own rules. This is the part of naming that the naming method saves for last, and it deserves more than a quick .com search.

Why a name can be available on one platform and not another

Every platform answers "is this handle available?" with its own rulebook:

• Which characters are allowed (periods, underscores, hyphens)
• How long a handle can be, and sometimes how short
• Where separators can go (start, end, twice in a row)
• Which names are reserved, held, or never released

Get one of these wrong and the name you announced is not the handle you can register.

The rules below are current as of October 2026. They come from two places: each platform's own documentation wherever it exists, and what we learned building and testing GarageExit's free name checker, where every rule on this page is enforced in code. Where a platform does not publish its rules, we say so.

Social media handle rules by platform

X

• 5 to 15 characters for a new handle
• Letters, numbers, and underscores only. No periods, no hyphens
• Underscores can go anywhere, including first and last (_garageexit and garageexit_ are both valid)
• Names containing "X" or "Admin" are reserved for official accounts

X is the strictest platform on this list, which makes it the best one to design around. A handle that works on X almost always works everywhere else.

Instagram

• Up to 30 characters
• Letters, numbers, periods, and underscores
• A period cannot start or end the handle, and two periods cannot sit next to each other
• Handles are not case-sensitive, so GarageExit and garageexit are the same account

Instagram's own help center suggests adding periods, numbers, or underscores when the name you want is taken. That makes garage.exit a legitimate brand handle on Instagram, and a dead end on X.

Instagram does not publish its length and period rules. The ones above are consistent across every independent guide we checked.

TikTok

• 2 to 24 characters
• Letters, numbers, underscores, and periods
• A period cannot be the last character
• You can change your username once every 30 days, and your profile link changes with it

All four come straight from TikTok's help center. Your TikTok username (the @handle in your profile link) is separate from your nickname, which is just a display name and does not need to be unique.

YouTube

• 3 to 30 characters
• Letters and numbers from YouTube's supported languages, plus underscores, hyphens, periods, and the Latin middle dot (·)
• Separators cannot be the first or last character
• Handles cannot look like a URL or a phone number

YouTube is the most permissive of the big platforms. Almost any brand name fits.

Product Hunt

Product Hunt does not publish its username rules. The safe assumption is letters, numbers, and underscores, the same as X. If your handle works on X, it works here.

Developer handles and package names

GitHub

• Up to 39 characters
• Letters, numbers, and hyphens. No periods, no underscores
• A hyphen cannot start or end the name, and two hyphens cannot sit together

If you plan to publish code, GitHub is where garage_exit quietly becomes garage-exit.

npm, PyPI, and crates.io

• npm: up to 214 characters, lowercase only, URL-safe characters. Unscoped names cannot start with a period or underscore
• PyPI: letters, numbers, periods, underscores, and hyphens, starting and ending with a letter or number. PyPI treats ., _, and - as the same character, so garage.exit, garage_exit, and garage-exit are one project
• crates.io: up to 64 characters, ASCII letters, numbers, hyphens, and underscores

These only matter if you ship a library or a CLI, but if you do, claim the name early. Package names are permanent in a way social handles are not.

Domain name rules

• Letters, numbers, and hyphens, up to 63 characters per label
• A hyphen cannot start or end the label
• No periods inside the name: garage.exit becomes garage-exit.com or garageexit.com

Very short names (three characters or fewer) are almost always taken or sold at premium prices, whatever the extension.

Five things we learned building a name checker

Rules on a help page are the easy part. These are the cases that only showed up once we ran real names against real platforms.

1. A handle can be "too short" and still taken

X requires at least five characters for new handles. Older accounts kept their shorter ones. Search for @fede and the availability check says the name is too short to register. The account still exists. Both are true, and a tool that only reads the rule will tell you the wrong thing.

2. Reserved words can still belong to someone

X reserves some words for new signups. marabunta comes back as a reserved word, yet a protected account already holds it. The handle is not "not allowed" for you because of the rule. It is taken, by someone who claimed it before the rule existed.

3. Separators split your brand

garage.exit is a valid, distinct handle on Instagram, TikTok, and YouTube. It is invalid on X, becomes garage-exit on GitHub, and garage-exit.com as a domain. If the separator is part of your brand, decide that early and accept that some platforms will drop it. If it is not, keep it out of the name entirely.

4. A trademark does not reserve a handle

Instagram states it plainly: usernames are first come, first served and cannot be reserved. Using a trademarked name only counts as a violation when it misleads people about a brand or business. Owning the trademark later will not hand you the handle someone else claimed first. Check every platform before you announce, not after.

5. Abandoned names do not come back on schedule

Neither Instagram nor TikTok publishes a timeline for releasing usernames held by inactive accounts. Instagram's guidance for an inactive account holding your name is to choose a variant. TikTok notes that names held by suspended or deactivated accounts may not be available immediately. Plan your fallback handle on day one instead of waiting for the original to free up.

How to pick a name that is available everywhere

• Design around X. Letters, numbers, and at most an underscore, 5 to 15 characters. A name that clears X clears almost everything else.
• Decide on separators deliberately. If you need a period to get the handle on Instagram, know that X and GitHub will not match it.
• Keep fallback affixes ready. try, use, get, and hq are the common ones: trygarageexit, garageexithq. Pick one pattern and use it consistently across platforms.
• Claim before you announce. Handles are first come, first served. The cost of registering five accounts early is zero. The cost of losing one after launch is a mismatched brand.
• Treat trademark checks as a first pass. A public trademark search shows possible conflicts, not legal clearance. If the name matters to the business, talk to a trademark attorney.

Check domains and social media handles in one pass

Doing this by hand means ten tabs and a spreadsheet. The free startup name checker checks domain availability and social media handles in one go: .com and nine other domain extensions, X, Instagram, TikTok, YouTube, GitHub, Product Hunt, npm, PyPI, crates.io, and a USPTO trademark search.

It applies each platform's own rules. Type garage.exit and it checks garage.exit on Instagram, garageexit on X, and garage-exit.com as a domain, and tells you before you run the check where a platform will change your name or cannot register it at all. When a handle is taken, it checks alternatives for you.

Treat the trademark result as a signal, not legal advice. Everything else is the kind of thing you want to know before the name is on your landing page, not after.