If you're trying to build an obby or a speedrun game, finding a reliable roblox custom stopwatch script is probably one of the first things on your to-do list. Let's be real, a game where people are competing for the fastest time doesn't really work if the timer is laggy or, even worse, inaccurate. Whether you're a seasoned developer or someone who just opened Roblox Studio for the first time, getting a timer to work exactly how you want it can be a bit of a headache if you don't know which functions to use.
The thing about Roblox scripting is that there are about a dozen different ways to do the same thing, but only a couple of those ways are actually efficient. If you've ever played a game where the timer seems to skip a second every now and then, it's usually because the developer used a simple wait(1) loop. We want to avoid that. We're going for something that looks professional, feels smooth, and gives players that millisecond-level precision they need to brag about their new personal best.
Why Accuracy Matters in Your Timer
Before we jump into the actual code, let's talk about why we aren't just using a basic counter. In the world of Luau (Roblox's version of Lua), time is a bit finicky. If you use a while true do loop with a task.wait(1), you're telling the script to wait at least one second. But because of server lag or frame drops, that "one second" might actually be 1.05 seconds. Over a five-minute run, those tiny delays add up, and suddenly your stopwatch is five or ten seconds off.
To fix this, a good roblox custom stopwatch script relies on os.clock(). This function is way more precise because it returns the CPU time in seconds since the program started. By grabbing a "start time" and comparing it to the "current time" every frame, you get a measurement that is incredibly accurate, regardless of whether the player's computer is sweating or the server is struggling.
Setting Up the UI
You can't really have a stopwatch if the player can't see it. You'll want to head over to the StarterGui in your explorer window. Right-click it, add a ScreenGui, and then throw a TextLabel inside.
Don't worry too much about the aesthetics yet—you can change the font and colors later—but make sure you name the TextLabel something logical like "TimerLabel." If you leave it as "TextLabel," you're going to get confused once your project gets bigger. Trust me, I've been there, and searching through fifty "Frame1" and "TextLabel" objects is a nightmare you don't want.
Once you've got your label positioned where you want it (usually top-center or bottom-right), it's time to actually get into the script.
The Core Scripting Logic
For a stopwatch, I usually recommend using a LocalScript. Since the timer is mostly for the player's own feedback, running it on the client side makes the numbers update much smoother. You don't want the timer waiting for the server to send back a message every fraction of a second just to update the UI.
Here's the general logic you'll want to follow. First, you define your variables. You need to reference the label we just made and set up a variable to track whether the timer is running or not.
lua local label = script.Parent -- Assuming the script is inside the TextLabel local running = false local startTime = 0 local elapsedTime = 0
Now, the "magic" happens in a loop. Instead of using a standard while loop, we should use RunService.RenderStepped. This is a specialized event that fires every single time the game renders a new frame. It's perfect for UI updates because it ensures the timer looks fluid.
Inside that loop, you'll calculate the difference between the current os.clock() and your startTime. This gives you the total seconds elapsed.
Formatting the Time String
This is where things get a bit "mathy," but don't panic. If your script just displays "65.438291 seconds," it's going to look terrible. You need to format it into minutes, seconds, and milliseconds.
You'll use the modulo operator (%) and math.floor to break the total seconds down. For example, to get minutes, you divide the total seconds by 60 and floor it. To get the remaining seconds, you use totalSeconds % 60.
The real secret sauce is string.format. It's a powerful tool that lets you force the text to look like "00:00.00". It ensures that if you have 5 seconds, it shows up as "05" instead of just "5," which keeps the UI from jumping around as the numbers change.
Adding Start and Stop Triggers
A roblox custom stopwatch script isn't very useful if it starts the second the player joins the server and never stops. You usually want it to trigger when a player touches a specific part (like a starting line) and stop when they hit the finish line.
To do this, you'll likely use RemoteEvents or simple Touched events. If you use a Touched event on a Part in the workspace, you can send a signal to your LocalScript to toggle the running variable to true.
One thing to keep in mind: Roblox's Touched event can be a bit sensitive. It can fire multiple times if a player's foot touches the part, then their leg, then their other foot. You'll want to add a "debounce" or a check to make sure the timer doesn't keep resetting itself every time the player takes a step on the starting line.
Handling Resets and Deaths
What happens if the player falls off the map? In most speedrun games, you want the timer to reset. You can easily hook into the player's Humanoid.Died event. When that fires, you just set running = false, reset elapsedTime to 0, and update the UI label back to "00:00.00".
If you want to get really fancy, you could save the player's "Best Time" using DataStores. This way, when they come back the next day, they can see the record they're trying to beat. But that's a whole other can of worms involving server-side scripting, so maybe save that for version 2.0 of your game.
Making it Look Pro
Once the logic is solid, you should spend some time on the "juice." Static text is boring. You could make the text change color when the player gets a personal best—maybe turn it gold or green. You could add a slight "pulse" effect using TweenService whenever a full minute passes.
Another small detail that makes a huge difference is the font choice. Roblox has added a lot of modern fonts lately. Something monospaced (where every character is the same width) is usually best for timers. Why? Because in many fonts, the number "1" is thinner than the number "8." If you use a non-monospaced font, your timer will jitter left and right as the numbers change. It's a small thing, but once you notice it, you can't unsee it.
Common Pitfalls to Avoid
I've seen a lot of people struggle with their roblox custom stopwatch script because they try to put all the logic on the server. While it's true that you need the server to verify times (to prevent hackers from just telling the server they finished in 0.1 seconds), the actual display should always be local.
Also, watch out for memory leaks. If you're connecting events every time the timer starts, make sure you aren't creating thousands of connections that never get cleaned up. Using a single RenderStepped connection that just checks an if running then condition is much cleaner and won't tank the player's FPS.
Final Thoughts
Building a stopwatch might seem like a small task, but it's actually a great way to learn about how Roblox handles time, UI, and player input. It's one of those foundational pieces of game design that you'll end up reusing in almost every project you work on.
Once you've got the hang of the basic roblox custom stopwatch script, you can start adding more complex features like split times for different sections of a map or a leaderboard that displays the fastest times across the whole server. The possibilities are pretty much endless, and it all starts with those few lines of code that keep track of the clock. So, get into Studio, start messing around with the code, and don't be afraid to break things—that's usually how the best learning happens anyway!