What is the EPK file format?
The .epk extension identifies the content half of an EterPack game-asset archive used by the popular MMORPG Metin2, developed by Ymir Entertainment and now operated by Webzen Games. .epk files store various types of data used by the game, including graphics, 3D objects, sounds and scripts, packed as raw binary blobs in a little-endian binary format.
An .epk file never works alone. It is always paired with a same-named .eix index file - the .epk holds the raw, encrypted asset bytes while its companion .eix holds the directory of filenames, offsets, sizes and decryption keys. To extract content, a tool must read and decrypt the .eix first; the .epk content file itself carries no header or magic bytes of its own.
Individual entries inside an .epk may be stored with per-entry LZO-style compression and encryption. The format version - EterPack v2, identified by the EPKD FourCC - is declared only in the paired .eix header.
.epk package files are saved in the game's installation directory under the /pack/ folder, typically split across many .epk/.eix pairs, each covering a different asset group.
Security & safety
RISK: MEDIUMGame EPK assets themselves are inert data, but the tooling around Metin2 EPK files is a risk zone: EterPack extractors and 'Metin2 tools' are commonly distributed on private-server forums and repack portals that bundle PUPs, keyloggers or game-account stealers. Download tools only from reputable sources (e.g. the established metin2.dev community / SourceForge), scan them, and never run random 'EPK opener' executables. Modifying official client files can also violate the game's terms of service.
Format details
in a nutshell- LG / Samsung TV/device firmware package - An .epk firmware update file used by LG (and some Samsung) TVs and devices - an encrypted firmware image, unrelated to Metin2.
- Enigma2 plugin/feed package - Linux set-top-box (Enigma2) software uses .epk-style packages for plugins/firmware; unrelated to the game format.
- Electronic press kit - Marketing 'EPK' (electronic press kit) bundles are sometimes saved with this extension, usually as a ZIP/PDF - not a game archive.
Programs that open EPK files
Windows3 apps
Metin2 (game client)
Free The game reads EPK/EIX automatically at runtime; just play - there's no manual 'open' for assets.
EterNexus (EterPack tool)
Free Load the matching .eix index; EterNexus uses it to extract the assets packed in the .epk. Requires the paired .eix.
Metin2 EPK/EIX Tool
Open-source Community unpacker/repacker for EterPack pairs; point it at the .eix to extract the .epk contents. Technical details
deep spec| Format type | Proprietary binary game-asset archive; content half of an EterPack pair |
| Byte order | Little-endian |
| Compression | Per-entry LZO-style compression applied to individual packed assets |
| Encryption | Per-entry encryption; the companion .eix index is a Crypted Object requiring decryption before parsing |
| File header / magic bytes | None - the .epk content file carries no header or magic signature of its own |
| Internal format version | EterPack v2, identified by the EPKD FourCC stored in the paired .eix header |
| Typical file size | 1 MB - 1 GB+ depending on the asset group |
| Pairing requirement | Always paired with a same-named .eix index file; cannot be unpacked independently |
| Asset types stored | Graphics, 3D models, sounds, scripts and other game client data |
| Install location | /pack/ subfolder of the Metin2 installation directory |
| MIME type | application/octet-stream |
| Platform | Windows (Metin2 client) |
| Developer | Ymir Entertainment (original); currently operated by Webzen Games |
| Extraction workflow | A tool reads and decrypts the .eix index first to obtain offsets, names and keys, then pulls blobs from the .epk |
| Released | 2004 (Metin2 launch in Korea; EterPack engine format) |
| Latest version | EterPack v2 (FourCC 'EPKD' in the .eix index); format used across Metin2 client versions |
| Specification | metin2.dev |
EPK conversions
Community Q&A
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