If you've been building on the platform for a while, you probably know that a roblox custom localization script is one of those things that sounds intimidating until you actually sit down and write one. Most developers start out relying on the built-in Automatic Translation tool, and don't get me wrong—it's a decent starting point. But the second your game starts getting complex, with dynamic UI elements or specific lore-heavy dialogue, that auto-translator usually starts tripping over its own feet.
The reality is that "one size fits all" rarely works for global games. If you want your player base in Brazil, Japan, or France to feel like they're playing a game made specifically for them, you need more control. That's where a custom script comes in. It lets you handle things exactly how you want, from the way text updates on the fly to how you store your translation strings.
Why the built-in tools sometimes fall short
Roblox provides a LocalizationTable, and while it's technically functional, it can be a bit of a nightmare to manage if you have thousands of lines of dialogue. Have you ever tried searching through a massive cloud table and realized it's just not updating fast enough? Or maybe you have a system where a player's name is inserted into a sentence like "Welcome, [PlayerName]!" and the auto-translator decides to translate the name itself? It's frustrating.
A custom localization script gives you the steering wheel. You can decide exactly when a piece of text gets updated. Instead of waiting for the engine to realize a TextLabel has changed, your script can push those changes the millisecond a player switches their language settings. Plus, it makes debugging way easier. If a string is missing, you can set up your script to print a warning in the output so you actually know what's broken.
Setting up the foundation
Before you dive into the code, you need a way to store your data. I'm a big fan of using a ModuleScript for this. It keeps everything neat, and you can require it from both the server and the client if needed (though localization is usually a client-side job).
Think of your ModuleScript as a massive dictionary. You'll have keys—which are usually English strings or unique IDs—and then values for each language you support. For example, your table might look something like this:
lua local Languages = { ["en"] = { ["WelcomeMessage"] = "Welcome to the game!", ["StartButton"] = "Play Now" }, ["es"] = { ["WelcomeMessage"] = "¡Bienvenido al juego!", ["StartButton"] = "Jugar ahora" } } return Languages
Using unique keys like WelcomeMessage instead of just the English text is a lifesaver. If you decide to change the English version from "Welcome to the game!" to "Glad you're here!", you don't have to go through and update every single reference in your scripts. You just update the dictionary value.
Building the core logic
Now, for the actual roblox custom localization script part. You need a manager script that can pull from that table and apply it to the UI. The most straightforward way is to have a local script inside StarterPlayerScripts or StarterGui that listens for language changes.
You'll want a function that takes a "Key" and returns the translated string based on the player's current language. But what happens if the player's language isn't in your table? Always, always have a fallback language. Usually, this is English. If your script looks for a Spanish translation and finds nothing, it should gracefully default to English so the player isn't just looking at a blank button or a weird technical ID.
It's also smart to hook into LocalizationService. You can use GetCountryRegionForPlayerAsync or check the player's locale, but honestly, giving players a manual toggle in a settings menu is usually the better move. People travel, or they might just prefer playing in a different language than their system default.
Handling dynamic text and variables
This is where things get a little tricky. Let's say you have a label that shows how many coins a player has: "You have 500 coins." You can't just translate that entire sentence because the "500" changes every five seconds.
The best way to handle this in your roblox custom localization script is using placeholders. In your language table, you'd write something like: ["CoinCount"] = "You have %d coins"
Then, in your script, you use the string.format function to plug in the number. This is much cleaner than trying to concatenate strings together, which often breaks the grammar in other languages. In some languages, the word order is completely different, so keeping the entire sentence structure in the translation string is the only way to make it sound natural.
Automating the UI updates
Manually telling every single TextLabel to update is a recipe for carpal tunnel. Instead, you can tag your UI elements. Using CollectionService is a total game-changer here. You can give every TextLabel that needs translation a tag like "Translatable."
Then, your script can just loop through everything with that tag. You can store the "Key" (like StartButton) in a StringValue inside the TextLabel. When the language changes, your script runs a quick loop, finds all the tagged labels, looks at their StringValue key, and pulls the right text from your ModuleScript. It's efficient, and it means when you add a new button to your shop, you just tag it and it works instantly without you writing a single new line of code.
Letting players choose
I can't stress this enough: give your players a choice. There's nothing more annoying than a game forcing a bad translation on you just because of your IP address.
Create a simple UI menu with flags or language names. When a player clicks "Japanese," your roblox custom localization script should update a variable, save it to a DataStore so it persists the next time they join, and then fire that update function we talked about. Seeing the entire UI flip from one language to another in real-time is actually pretty satisfying to watch, and it makes your game feel incredibly polished.
Performance considerations
You might be worried that looping through every piece of text in your game will cause lag. Don't be. Unless you have tens of thousands of labels (which would be a UI disaster anyway), the overhead is tiny. Computers are very, very fast at looking up items in a table.
The only thing to watch out for is making sure you aren't running the translation logic every single frame. Only trigger it when: 1. The player first joins. 2. The player manually changes the language. 3. A new UI element is cloned/added to the screen.
If you handle it those three ways, your performance impact will be basically zero.
Final thoughts on going global
Writing a roblox custom localization script is one of those "level up" moments for a developer. It shows you're thinking about your audience and the long-term scalability of your project. It's not just about the code; it's about making sure someone on the other side of the world can enjoy your game without having to pull out a translation app.
It takes a bit of extra work up front to set up the tables and the tags, but once the system is running, it becomes second nature. You'll find that it actually makes your development process faster because you have a centralized place for all your text. No more hunting through dozens of ScreenGuis to find that one typo—you just fix it in the ModuleScript and you're done.
So, if you haven't already, give the custom approach a shot. Your players will definitely notice the difference, and your game will feel a lot more professional because of it. Keep it simple, keep it organized, and don't forget to have someone double-check your translations if you're using a tool to generate them! There's nothing worse than a button that accidentally says something it definitely shouldn't.