Start here
Work out whether it’s Roblox or the way you’re starting it
Try to launch the same experience a second way — from the website if you normally use the app, or from a different browser if you normally use the website. That splits the problem immediately. If it starts one way and not the other, Roblox and your account are fine and the fault is that browser, its extensions, or the installed client. If it fails every way, look past the launcher: Roblox's own guidance points at the firewall, which it describes as very frequently the cause of loading problems.
Applies to: Roblox on Windows and macOS, launched from the desktop client or from a browser. Console and mobile apps have their own troubleshooting; the browser, firewall and reinstall guidance below is desktop-specific.
Where does it stop?
“Roblox won’t launch” covers a click that does nothing, a client that opens and hangs on the loading screen, and an experience that reaches 100% and then drops you back. They have different causes — a browser handoff, a corrupted install, and a blocked connection respectively — and the fastest way to tell them apart is to change one thing about how you start it and see whether the failure follows.
Clicking play does nothing at all
Does it work from a different browser?
Change the routeIt opens and hangs on loading
Is an ad-blocker or extension interfering?
Check extensionsIt loads then disconnects
Is the firewall blocking Roblox’s ports?
Check the firewallNothing helps and errors persist
Has it been reinstalled after clearing the cache?
Reinstall it1. Restart, then change how you launch it
Roblox's guidance opens with the least interesting and most effective step: reboot the computer and try to play, because sometimes that is all that is needed. It clears a stuck client process, a half-loaded update and a wedged network state in one action, and it costs less than any of the diagnosis that follows.
Then change the route. If you normally launch from the desktop client, start the same experience from the Roblox website instead; if you normally use the website, try a different browser. Roblox suggests trying another browser such as Microsoft Edge, Firefox or Chrome, and the reason it helps diagnostically is that each route uses a different set of components — a failure that follows you across all of them is not a browser problem.
Keep the browser current while you are at it. Roblox's guidance is to use the most updated version of your browser to play, and an old browser is a genuine cause rather than boilerplate — the web client depends on features that move. If launching works in a second browser, you have isolated the fault to the first one, and sections 2 and 3 are where to look.
Note exactly where it stops: nothing happens at all, the client opens and hangs, or the experience loads and then drops you. Those three point at the handoff, the install, and the connection respectively.
2. Extensions, ad-blockers and browser security
Roblox names this directly: browser add-ons and extensions can cause issues, and ad-blockers in particular can stop an experience from fully loading. That is a specific and useful claim — an ad-blocker does not usually break a site outright, so the failure it produces here looks like a Roblox fault rather than a blocked request.
Test in a private or incognito window, which usually runs with extensions disabled, before disabling anything permanently. If it launches there, an extension is responsible and you can re-enable them one at a time to find which. Ad-blockers, privacy extensions, script blockers and VPN browser extensions are the usual candidates.
Browser security settings matter too. Roblox's guidance is to ensure the security settings on your browser allow for Roblox, noting that settings set too high cause various problems. That covers strict tracking prevention and content blocking as much as anything labelled security, and both are increasingly on by default in modern browsers.
3. Clear the cache, and why it matters here
Roblox's guidance is to clear the browser's temporary internet files, which it says helps with corruption issues. That wording is worth taking literally: the problem being solved is not stale content but a partially downloaded or damaged file that the browser keeps serving from disk. A corrupted cached asset produces a loading screen that never completes and survives every restart, because the bad file is reused each time.
Clear the cache rather than just the history — they are separate options in most browsers, and history alone leaves the cached files in place. On Chrome and Edge that is Settings → Privacy → Clear browsing data with Cached images and files ticked; on Firefox it is Settings → Privacy & Security → Cookies and Site Data → Clear Data.
Do this before reinstalling anything. Roblox's own sequence puts clearing the cache before uninstalling and reinstalling, and the order is deliberate — a reinstall that pulls the same corrupted file from a cache achieves nothing, which is why reinstalling sometimes appears not to help.
Clearing the cache signs you out of sites. That is expected rather than a side effect to avoid, but have your Roblox password to hand before you do it.
4. The firewall, and the ports Roblox needs
This is the most concrete thing in Roblox's documentation and the least widely known. Roblox states that the firewall is very frequently a cause of loading problems, though it can also be a low-bandwidth or inconsistent wireless connection. If an experience reaches the loading screen and then fails or disconnects, this is where to look rather than at the browser.
Roblox publishes the port range it uses: UDP 49152 to 65535. Keeping all of those ports open should allow Roblox to connect to your router properly. That range is unusually wide and is exactly the sort of thing a restrictive firewall, a school or workplace network, or a router with aggressive filtering will block — often silently, which is why the failure gives no useful message.
Test the network rather than guessing at rules. A phone hotspot is the fastest way: if Roblox launches on a hotspot and not on your home or school network, the network is the fault and no amount of reinstalling will change it. On a managed network — a school, a library, an office — that is usually the end of the road, because the block is deliberate.
Port range
Roblox uses UDP 49152–65535. Blocking any of it causes loading and connection failures.
Fast test
Try a phone hotspot. Working there and not on your usual network identifies the network conclusively.
5. When it launches and looks wrong
A client that starts and then crashes, shows a black screen, or renders badly is a graphics problem rather than a launching one, and Roblox documents it separately. Updating the graphics driver is the first move — not Windows Update, but the driver from the graphics card manufacturer, which is frequently well behind.
Roblox has its own graphics settings that are worth lowering as a test. If the client is stable at low graphics quality and unstable at high, you have found a resource limit rather than a fault, and that is common on older laptops and on machines with integrated graphics sharing system memory.
Overlays are a specific and under-appreciated cause of crashes at launch. Discord's game overlay, GeForce Experience, Steam's overlay and various recording tools all inject themselves into the game process, and any of them can crash it. Disable them one at a time if the client dies at or shortly after startup.
6. Reinstalling properly, and what to tell support
Reinstalling is Roblox's later step rather than an early one, and the sequence matters: clear the browser cache first, then uninstall and reinstall to resolve corruption issues. Doing it the other way round is why a reinstall sometimes changes nothing — the corrupted file is still cached and comes straight back.
Uninstall cleanly rather than installing over the top. Remove Roblox through the operating system's normal uninstall route, restart the machine, and then download a fresh copy from the Roblox website rather than reusing an old installer. On macOS, Roblox publishes its own troubleshooting article, since the paths and permissions differ from Windows.
When you contact Roblox support, describe where it stops. Say whether clicking play does nothing, whether the client opens and hangs, or whether the experience loads and then disconnects; whether it works in a different browser or from the client instead of the website; whether it works in a private window with extensions disabled; whether it works on a phone hotspot; and whether you cleared the cache before reinstalling. Those five answers separate a browser problem from a corrupted install from a blocked network.
Frequently asked questions
Why won’t Roblox launch?
Change how you start it — from the website if you normally use the app, or a different browser if you normally use the website. If it works one way and not the other, Roblox and your account are fine and the fault is that browser or the installed client. If it fails every way, Roblox's guidance points at the firewall, which it describes as very frequently the cause of loading problems.
Why does Roblox get stuck on the loading screen?
Two common causes. Roblox names ad-blockers specifically as able to stop an experience from fully loading, so test in a private window with extensions disabled. The other is a corrupted cached file, which is why Roblox's guidance is to clear the browser's temporary internet files — a damaged file gets served from disk again on every attempt, so it survives restarts.
What ports does Roblox need open?
UDP 49152 to 65535. Roblox publishes this range and says keeping all of it open should let the client connect to your router properly. It's wide enough that restrictive firewalls, school networks and filtering routers often block part of it — usually silently, which is why the failure gives no useful error.
Roblox works on my phone but not my computer. What does that mean?
Your account and Roblox itself are fine, so the fault is on the computer or its network. Narrow it further with a phone hotspot: if the computer works on the hotspot and not on your usual Wi-Fi, it's the network — most likely a firewall blocking Roblox's UDP port range. If it fails on both, it's the browser or the installed client.
Should I reinstall Roblox?
Only after clearing the browser cache, and Roblox's own sequence puts it in that order for a reason: a reinstall that pulls the same corrupted file from cache achieves nothing, which is why reinstalling sometimes seems not to help. Uninstall properly, restart, then download a fresh copy rather than reusing an old installer.
Roblox opens then crashes. Is that the same problem?
No — that's a graphics or overlay problem rather than a launching one. Update the graphics driver from the card manufacturer rather than relying on Windows Update, and lower Roblox's graphics quality as a test: stable at low and unstable at high means a resource limit. Then disable overlays from Discord, GeForce Experience or Steam, which inject into the game process and can crash it.
Sources and review notes
Checked on . Compiled by Glitchary from Roblox’s support documentation. Roblox updates its client frequently and browser menu paths differ by browser and version — check Roblox’s current article if a step does not match what you see. Guidance on overlays, private browsing and graphics drivers reflects general practice rather than Roblox documentation, and changes to firewall or router configuration on a managed network need whoever administers it. Glitchary is independent of Roblox.