Switch to 64-bit Garry's Mod
Garry's Mod starts out as a 32-bit game. We recommend the free 64-bit version with Chromium: it uses more of your memory, crashes less with big content like ours and has a modern in-game browser. Switching takes a couple of minutes in Steam.
Why switch
More memory
The standard version is 32-bit, so it can only use about 4 GB of memory however much your PC has. The 64-bit version can use all of it, which stops most out of memory crashes on big maps and with large content packs.
A modern in-game browser
Menus, loading screens and in-game web pages run on Chromium instead of a browser from 2012, so websites, videos and music players work as they should.
Smoother on busy servers
With room to breathe, the game often runs smoother on large maps and full servers, and stutters less as content loads.
Step by step
You'll need a 64-bit operating system, which almost every computer from the last ten years has. Close Garry's Mod first if it's open.
Step 1: Open the game's properties
In your Steam library, right-click Garry's Mod and choose Properties. You can also open the cog on the game's page and choose it there.
Right-click Garry's Mod in your library, then choose Properties. Step 2: Open Game Versions & Betas
Choose Game Versions & Betas on the left. In older versions of Steam it's called Betas.
The Game Versions & Betas tab in the Properties window. Step 3: Choose the 64-bit version
Open the Beta Participation list and choose x86-64 - Chromium + 64-bit binaries. It's free and doesn't need an access code.
Pick x86-64 - Chromium + 64-bit binaries from the list. Step 4: Let Steam update the game
Close the Properties window. Steam starts downloading the 64-bit files straight away, and the game shows as Garry's Mod [x86-64] in your library. Wait until it finishes and the Play button comes back.
Steam updating Garry's Mod, now marked x86-64 in the library. Step 5: Play the 64-bit version
Press Play. If Steam asks which version to start, choose the 64-bit one. That's it: you're on 64-bit Garry's Mod, and Steam keeps it up to date from now on.
If Steam asks how to start the game, choose the 64-bit version.
Good to know
Your things are safe
Addons, saves, dupes and settings all carry over. Switching only changes the game's own files.
An addon stopped working
A few old addons come with their own 32-bit modules, which can't load in the 64-bit version. Workshop content like maps, models and weapons isn't affected.
It crashes or won't start
In Properties, open Installed Files and choose Verify integrity of game files, then try again. If the update never started, restart Steam.
Switching back
Follow steps 1 to 3 again and choose None. Steam downloads the standard version and everything else stays as it was.
Still stuck? Players and staff on Discord are happy to help. Our help and FAQ page may already have the answer.