This is a simple username sniper which I created with roact, rodux, otter and roact rodux in order to help learn the libraries which I have just stated.
It features the ability to change the username length, display rejected usernames, use underscores, and use numbers. There is also copy paste functionality; the username is literally in a textbox - ctrl c and v it… simple!
I may add more options in the future.
Nice, really useful I can now have a 4 letter username thanks so much, 
Please add dark mode feature because my eyes hurt when I joined the game. its too bright.
Yes. That is definitely on the to-do list.
There’s a problem where it repeats the same username, and also some usernames cant be used because Roblox puts them as ‘inappropriate’. Overall, really cool!
The permutations of a 3 or 4 letter username are already taken.
If there are any on the resource, it would be marked “inappropriate” when typed on ROBLOX.
visited and gave a like
its a neat concept
As a response to the OP regarding the picture you showed, due to all 4 letter usernames already being taken, it seems like the OP did not use correct API to validate available usernames. OP, as a suggestion, I recommend you use this for validation:
https://auth.roblox.com/v1/usernames/validate?context=UsernameChange&username=Fk_f
Thank you. I will make changes accordingly.
Thank you this is way faster and helpful than the rest I’ve seen.
I’m getting some names that have a random letter at the front (e.g. “U”) and then a word one letter away from the f-word, does it run through a filter before displaying?
Considering I just got a letter combination that I know is filtered, I’ll tell you this: generators can get banned for not having a filter like this, so I’d recommend you add one.
Not bad. If you use this choose 5 letter words. 4 letter words have all been taken. One of the last 4 letter names was 2gvr.
Yes, I am aware of this. I’m actively working on a solution. Expect an update in a few hours.
It’s not a bad username sniper, the white hurts my eyes quite a bit though. Also, it’s a decent bit slower than some other username sniping games I’ve seen.
You should use Chat:FilterStringAsync to solve this, or make an external web call to listen to if the username is appropriate or not:
https://auth.roblox.com/v2/usernames/validate?request.username=REQUEST_HERE&request.context=Signup
I recommend the endpoint because you can use it to both check if the username isn’t taken and check for appropriateness and whether or not it should be displayed. One asynchronous call is faster.
Quick update: Now filters innapropriate usernames.
Replaces the actual username with a placeholder.
This is really neat for what it is, but 4 letter usernames shouldn’t be an option due to the fact there are none left available. Even though this sniper says they are, they aren’t and always come up as taken, or inappropriate for me. I know you updated for the inappropriate part, but it still tells me they are when I try to test to see if this works or not. This was a pretty solid attempt though, even for being fresh, and new!
-Void_Xiety 
Thanks for the feedback, yesterdays patch was supposed to be a temporary fix, I’ll soon be switching to the api endpoint instead to validate usernames which should give more consistent results.
Sounds like a great idea. I’d definitely give the new one a try, and give some more feedback, and display bugs if any.
NEW UPDATE
The username sniper now uses the Roblox endpoint api to validate usernames. The caveat of this is ufortunately slower generation times. Each request takes 200 - 1000 ms on average to be responded to. However, the results of the generator should be far more accurate in terms of name appropiabililty and availablity (provided someone does not register an account with a generatred name before you do).
