What is an EPK file in Minecraft?
EPK files are not part of vanilla Minecraft. If you've encountered one, it came from Eaglercraft, a project originally created by a developer known as "lax1dude" that translates Minecraft's Java code into JavaScript so it runs in any web browser, including school Chromebooks.
Every Eaglercraft build ships with a file called assets.epk containing the compiled resources needed to run the game. Separately, players can export their singleplayer worlds as .epk files to back them up or transfer them to another device.
The .epk extension is also used by LG TV firmware and Metin2 (an MMORPG), but in the Minecraft context it's always Eaglercraft-related. Eaglercraft itself operates in a legal grey area regarding Mojang's IP. This guide explains the file format without promoting or discouraging the project.
How EPK files work
There are two distinct types of EPK files, and they work quite differently under the hood:
Asset EPK files (assets.epk)
- Compressed archives (gzip or zlib) containing game textures, sounds, and models
- File header uses the signature
EAGPKG$ - Include CRC32 integrity checks for file validation
- Required for every Eaglercraft deployment. Without it, the game can't load
World EPK files
- Use no compression: the data is stored raw
- Contain NBT (Named Binary Tag) data, the same format vanilla Minecraft uses for world saves
- Two sub-types based on Eaglercraft version:
epk/world152: Eaglercraft 1.5.2 worldsepk/world188: EaglercraftX 1.8.8 worlds
How to open and extract EPK files
EPK files aren't natively supported by any standard archive tool. Here are four methods that work, from simplest to most capable:
Rename to .zip (quick check)
Some EPK files are essentially renamed ZIP archives. Rename .epk to .zip and try opening with 7-Zip, WinRAR, or your OS's built-in extractor. This works for some asset packages but will not work for all EPK files, especially world backups with custom headers.
ayunWebEPK (browser-based)
A web tool by ayunami2000 that can compile and decompile EPK files directly in your browser. No installation required. Just upload your file and extract. The easiest option if you don't want to touch the command line.
Eagler Binary Tools (command line)
The official open-source toolkit by lax1dude for working with EPK, EBP, MDL, and other Eaglercraft formats. Includes epkdecompiler with automatic format detection for both modern and legacy EPK files.
epkdecompiler <input file> <output directory>Eaglercraft Save Editor (browser-based, for world files)
A web-based tool by ayqshi for extracting, viewing, editing, and repacking EPK world files. Can parse .dat (NBT) files and display them as human-readable JSON. Lets you modify world data and repack into a new EPK. Currently in beta.
How to import and export EPK world files
The most common reason people encounter EPK files: backing up and transferring Eaglercraft worlds between devices or browsers.
Exporting a world
- Open Eaglercraft singleplayer
- Go to the world selection screen
- Select your world and click "Backup"
- Save the
.epkfile to your device
Importing a world
- Open Eaglercraft singleplayer
- Click "Create New World"
- Select "Load World Backup"
- Upload your
.epkfile - Name your world and click Continue
Exported worlds can be imported on any Eaglercraft site that supports singleplayer (such as eaglercraft.com). You're not locked to the site you originally played on. EaglercraftX can also import vanilla Minecraft 1.8 worlds as ZIP files.
Eaglercraft worlds are stored in your browser's IndexedDB. Clearing browser data, switching browsers, using incognito mode, or school IT policies wiping cache will delete your worlds permanently. Export backups as EPK files regularly.
How to create or modify EPK asset files
If you want to customise Eaglercraft with your own textures or sounds, you'll need to compile a new assets.epk:
- 1Locate the resources directory in your Eaglercraft installation:
eaglercraft-beta-main/lwjgl-rundir/resources - 2Place your custom assets (textures, sounds, etc.) in the appropriate subdirectories
- 3Run
epkcompiler/run.bat(Windows) orrun_unix.sh(Mac/Linux; runchmod +x run_unix.shfirst) - 4Replace the existing
assets.epkin your Eaglercraft deployment with the newly compiled file
Alternatively, use ayunWebEPK to compile EPK files directly in your browser without command-line tools. For EaglercraftX 1.8, you can also import vanilla Minecraft 1.8 resource packs as ZIP files directly. No EPK compilation needed for simple texture swaps.
EPK files vs other Minecraft file formats
EPK is Eaglercraft-specific and not interchangeable with vanilla Minecraft formats. Here's how it compares:
| File format | Used by | Purpose |
|---|---|---|
| .epk | Eaglercraft (browser Minecraft) | Asset packages & world backups |
| .mcworld | Bedrock Edition | World export/import |
| .dat / .mca | Java Edition | World save data (NBT/Anvil format) |
| .zip (world) | Java Edition | World folder compressed for sharing |
| .mcpack | Bedrock Edition | Resource/behaviour pack import |
| .jar | Java Edition (mods) | Mod files and client JARs |
Frequently asked questions
Can I open an EPK file in regular Minecraft?
No. EPK is an Eaglercraft-specific format. Vanilla Minecraft Java Edition uses .dat and .mca files for world saves, and .zip or folder structures for sharing worlds. You cannot load an EPK directly into Minecraft Java or Bedrock Edition.
Where can I play Eaglercraft?
Eaglercraft can be played directly in a web browser at eaglercraft.com. It supports singleplayer worlds with EPK import/export, resource packs, and multiplayer servers. No download or installation required.
Are EPK files safe to download?
EPK files from trusted Eaglercraft sources are generally safe: they contain game assets or world data, not executable code. However, be cautious downloading EPK files or Eaglercraft clients from unknown sources, as some unofficial forks have been known to contain malware. Only download from GitHub repositories you trust.
Can I convert an EPK world to a regular Minecraft world?
Yes, with extra steps. Use Eagler Binary Tools or ayunWebEPK to decompile the EPK, which gives you the raw NBT world data. This data uses the same format as vanilla Minecraft saves, so it can potentially be loaded into a regular Minecraft 1.8 world folder. The reverse is also true: EaglercraftX can import vanilla 1.8 worlds as ZIP files.
Why did my Eaglercraft world disappear?
Eaglercraft stores worlds in your browser's IndexedDB storage. If you cleared your browser data, switched browsers, used incognito mode, or your school's IT policy wiped cached data, your world is gone. This is the number one reason to export world backups as EPK files regularly.
What's the difference between assets.epk and a world .epk?
assets.epk contains the compiled game resources (textures, sounds, models) needed to run Eaglercraft. A world .epk is a backup of a specific singleplayer world containing terrain, builds, inventory, and other save data. They use the same file extension but serve completely different purposes.
The one thing to remember: Eaglercraft worlds live in your browser and can vanish without warning. Export your builds as EPK backups before they disappear.
Looking for Minecraft maps to play?
Browse maps
