Open GMA files in your browser
The file a Garry's Mod addon comes as, from the Steam Workshop or a server. Open one right here to see what's inside, without the game. Nothing leaves your device.
Or drop it anywhere on this page
What you'll see
Your file opens like a folder, its files listed on the left, with a page beside them on what it is and what it holds.
- Listed like a folder • Unpacks only what you pick
- A page on what it is • From its own manifest or index
- Pictures, sounds and text • Each opens in its viewer
- Export • Save as ZIP or Extract all
About GMA
Garry's Mod 13 brought addons to the Steam Workshop in 2012, and each one since is a GMA file: tools, weapons, models, maps and game modes. The Workshop sends them packed with LZMA, and the game keeps them in its cache.
A GMA starts with GMAD and its version, the Steam ID of its maker and when it was made, then its title, a description in JSON with its type and tags, and its author. After that come each file's path, size and CRC, then the files one after another: Lua scripts, Source models, materials, sounds and maps.
Filepeek unpacks a Workshop copy's LZMA first, reads the header and lists the files in their folders. The page shows the title, type, tags and when it was made, and counts the files by kind. Models, materials, sounds and pictures open in their own viewers, and Lua scripts as text, never run.
Garry's Mod addon
.gma
Format
- MIME type
- application/octet-stream
- Made by
- Facepunch Studios
- Released
- 2012
Inside the file
- Starts with
- GMAD and its version
- Header
- Title, type, tags and author
- Files
- A path, size and CRC, then the data
- From the Workshop
- Packed with LZMA
Opens in every browser
Filepeek opens a GMA as a folder in Chrome, Edge, Firefox and Safari. On their own, browsers only download it.
- YouChromeOpens through Filepeek
- YouEdgeOpens through Filepeek
- YouFirefoxOpens through Filepeek
- YouSafariOpens through Filepeek
Apps that open GMA
- Windowsgmad, with Garry's Mod • Crowbar
- Macgmad, with Garry's Mod
- iPhone and iPadNo app opens it
- AndroidNo app opens it
Questions
How do I open a GMA file?
Drop it on this page or choose Peek a GMA, as it came from the Workshop or an addon's folder. Its files are listed in their folders.
Do its Lua scripts run?
No. They open as text, like any other file of the addon, and nothing in it runs.
Can I extract it?
Yes. Extract all writes every file into a folder in Chrome and Edge, and Save as ZIP works everywhere. gmad, which comes with the game, unpacks it too.