CAK File

What are CAK files and how to open them

Are you having problems opening a CAK file or are you simply curious about its contents? We're here to explain the properties of these files and provide you with software that can open or handle your CAK files.

What is a CAK file?

A .CAK file is a Sega FILM Video file.

A Sega FILM Video File (extension .cak) is a multimedia container used by Sega in early CD-based video game systems, primarily the Sega CD and Sega Saturn. It holds full-motion video sequences (sometimes with audio) used for in-game cinematics, intros, cutscenes or other pre-rendered video content in Sega's proprietary FILM/CPK format, which game developers embed into the game disc.

These files are created by Sega's tools (or the game's build tools) when assembling game data to produce assets for a Sega CD or Saturn title. During gameplay, the system reads the .cak file, decodes video (often using Cinepak or similar codecs) and plays the video stream (and audio, if present). For anyone extracting or preserving old game content, .cak files are what you'd find among the FILM/CPK assets.

Internally, Sega FILM files start with a header identifying the FILM/CPK container; multi-byte integers are stored in big endian order. Video data may be Cinepak-compressed frames, interleaved with uncompressed PCM audio if the version includes audio. Extensions associated with this format include .cak, .cpk, .film.

How to open CAK files

We have identified one CAK opener that is compatible with this specific type of CAK file.

Programs that open Sega FILM Video files

Last updated: August 5, 2026

Various apps that use files with this extension

These apps are known to open certain types of CAK files. Remember, different programs may use CAK files for different purposes, so you may need to try out a few of them to be able to open your specific file.

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