Getting a roblox custom input filter script working properly is one of those things every developer realizes they need about five minutes after opening their game to the public. If you've ever seen a chat box filled with spam or players trying to bypass the basic filters with weird symbols, you know exactly why this matters. It's not just about stopping "bad words"—it's about making sure your game stays compliant with Roblox's Terms of Service while keeping the community from turning into a chaotic mess.
Roblox actually does a lot of the heavy lifting for us with their built-in TextService, but implementing it into your own custom UI or special game mechanics requires a bit of a setup. You can't just slap a text box on the screen and hope for the best. If you're building a custom chat, a pet naming system, or even a bulletin board, you need a robust way to handle that text.
Why You Can't Skip the Filter
Let's be real for a second: Roblox is pretty strict about text filtering. They have to be. Since the platform has a huge audience of younger kids, the "hashes" (the infamous ###) are a necessary evil. If you try to bypass these filters or if you forget to implement a roblox custom input filter script for user-generated text, your game could get flagged or even taken down.
The filter isn't just a suggestion; it's a requirement. If a player types something and another player sees it, that text must go through the Roblox filter API. The cool thing is that the filter is actually quite smart. It adjusts based on the age of the player viewing the text. A 13+ player might see something that a younger player sees as tags. Setting up your script to handle these nuances is what separates a professional-feeling game from a buggy one.
The Basic Logic of Filtering
When you're writing your script, you have to think about the journey the text takes. It starts at the player's keyboard (the Client) and has to end up on everyone else's screen (other Clients). But you should never filter on the client side. Why? Because hackers can easily bypass client-side scripts.
The flow always looks like this: 1. Player types something into a TextBox. 2. The Client sends that string to the Server via a RemoteEvent. 3. The Server receives the string and runs the roblox custom input filter script using TextService. 4. The Server sends the "safe" version of the text back to the other players.
If you skip the server step, you're basically leaving your front door unlocked. Always do the heavy lifting on the server.
Setting Up TextService
To get started, you're going to be spending a lot of time with TextService:FilterStringAsync(). This is the meat and potatoes of any custom filtering system. This function takes two main arguments: the string of text you want to filter and the UserID of the player who wrote it.
Here's the catch: FilterStringAsync doesn't just give you back a clean string immediately. It gives you a TextFilterResult object. From that object, you can decide how to distribute the text.
Filtering for a Specific Receiver
If you're sending a private message or something that only one person will see, you'd use GetChatForUserAsync(). This checks the age and settings of the person receiving the message. It's the most accurate way to make sure the right people see the right things.
Filtering for Everyone
For things like a global announcement or a message in a public chat room, you'd use GetNonChatStringForBroadcastAsync(). This is the "strictest" version of the filter. Since the server doesn't know who might see this text in the future (like someone joining late), it filters it so it's safe for literally everyone, regardless of age.
Writing the Script
When you sit down to write your roblox custom input filter script, keep it clean. You'll want a ModuleScript in ServerStorage or a regular Script in ServerScriptService.
You start by getting the service: local TextService = game:GetService("TextService")
Then, you create a function that handles the request. You should wrap your filtering call in a pcall (protected call). This is super important because FilterStringAsync is a web call. If Roblox's servers are having a hiccup or if the internet blips, your entire script will crash if you don't use a pcall.
Imagine your game's chat breaking completely just because one web request failed—not a great look. By using a pcall, you can catch the error and maybe return a default "Filter Error" message instead of breaking the game.
Handling the UI Side
Once your server has the filtered text, you need to get it back to the players. This is where your UI design comes in. If you're building a custom chat, you'll probably have a ScrollingFrame where you're instantiating new TextLabels.
Make sure your TextLabels have TextWrapped turned on, otherwise long messages will just disappear off the side of the screen. Also, a little tip: when the text comes back from the server, it might be a bunch of hashes. Don't try to "fix" it or hide it. If the filter says it's tags, let it be tags. Trying to replace hashes with something else can sometimes get you in trouble with the automated moderation systems.
Common Pitfalls to Avoid
I've seen a lot of devs make the same mistakes when setting up a roblox custom input filter script. The biggest one is definitely over-filtering. You don't need to write your own list of "bad words." In fact, you shouldn't. Roblox's filter is updated constantly and handles multiple languages. If you try to build your own list, you'll miss things, or worse, you'll accidentally block perfectly normal words.
Another mistake is spamming the filter. You shouldn't be filtering text every single time a player presses a key. Wait until they hit "Enter" or click "Submit." Every time you call FilterStringAsync, you're making a request. If you do that 60 times a second, you're going to hit rate limits, and your filtering will just stop working.
Adding Some Polish
If you want your input system to feel professional, add some feedback for the user. If they try to submit a message that's too long, show a little red text warning. If the filter returns nothing but hashes, maybe don't make a loud "ding" sound that draws attention to it.
You can also add a "cooldown" or "debounce" to your RemoteEvent. This prevents a player from firing the event 100 times a second and lagging the server. A simple task.wait(0.5) on the server-side logic for each player is usually enough to keep the spam at bay.
Keeping it Secure
Always remember that the player's UserID is a crucial part of the roblox custom input filter script. Don't let the client tell the server what the UserID is. The server already knows who sent the RemoteEvent through the first argument passed to OnServerEvent. If you trust the client to tell you who they are, a malicious player could pretend to be someone else, which is a massive security hole.
Wrapping Things Up
Creating a roblox custom input filter script might feel like a chore compared to making cool explosions or fun movement mechanics, but it's the backbone of a safe game. It protects your players, it protects your account from moderation, and it keeps the game environment clean.
Once you have a solid template for filtering text, you can reuse it in every project you work on. Whether it's for a simple sign in a tycoon game or a complex global trade chat in an RPG, the principles remain the same: Stay on the server, use pcall, and respect the TextService results.
It's one of those "set it and forget it" systems. Once it's working, you won't have to worry about it again, and you can get back to the fun parts of game development—actually building the world. So, get that script running, test it with a few friends, and make sure those hashes are working exactly where they should be!