CAP File

What are CAP files and how to open them

Are you having problems opening a CAP 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 CAP files.

What is a CAP file?

CAP files have multiple uses, and Scirra Construct Game Data is one of them. Read more about the other uses further down the page.

Scirra Construct Game Data File

The .cap file extension is most commonly used for game development files. These files are created by the Scirra Construct programming application to create DirectX 9-based computer games.

The CAP files contain the background images, objects, event handlers, physics models, and other code used to create the game.

How to open CAP files

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

Programs that open Scirra Construct Game Data files

Last updated: August 5, 2026

All known file formats using extension .CAP

While Scirra Construct Game Data File is a popular type of CAP-file, we know of 9 different uses of the .CAP file extension. Different software may use files with the same extension for different types of data.

Capella Music Notation

We know that one CAP format is Capella Music Notation. We have not yet analyzed in detail what these files contain and what they are used for. We're working on it.

While we have not verified the apps ourselves yet, our users have suggested ten different CAP openers which you will find listed below.

Capella Music Sheet File

Capella Music Sheet File (extension .CAP) is a proprietary binary file format used by the Capella music notation program (by capella-software AG) for saving musical scores prior to Capella 7. These files store complete musical scores including notes, rests, chords, staffs, time-signatures, lyrics, and layout information for playback, editing, and printing.

Files with this extension are created by older versions of Capella (for example Capella versions through 2000-2006) using its Binary CAP format, which preceded the XML-based CapXML format (extension .CAPX) introduced in Capella 7. Users continue to open, edit, print or play .CAP files using Capella or Capella Reader, though newer versions favor the .CAPX format.

Internally the .CAP binary files begin with the ASCII signature "cap3‐v:a" at offset zero (also containing the string "CAP3-V:A"), which identifies them as the CAP3 version of Capella's binary score format.

CAP opener for Windows

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

IBM Storyboard Screen Capture File

We know that one CAP format is IBM Storyboard Screen Capture File. We have not yet analyzed in detail what these files contain and what they are used for. We're working on it.

Java Card Converted Applet

We know that one CAP format is Java Card Converted Applet. We have not yet analyzed in detail what these files contain and what they are used for. We're working on it.

Microsoft NetMon Traffic Capture File

Microsoft NetMon Traffic Capture files with the extension .CAP store raw network traffic captured by Microsoft Network Monitor. These files are produced when a user captures packets on one or more network adapters using Network Monitor (for example version 3.4) and then saves the capture session. Their main purpose is to record all frames seen on the selected adapters, including protocol details, timing, and any user or comment metadata, for later examination and troubleshooting. Network Monitor is a protocol analyzer used to collect, view, and analyze network traffic on Windows.

Inside a .CAP file, the data is organized in several segments: a global header that describes version, network medium, and capture start-time; an index (frame table) that locates each frame inside the file; followed by the frame data themselves, plus optional segments for user data, comments, statistics, and network information. After capturing, one typically loads the .CAP file into Network Monitor or another compatible tool to filter, analyze protocol exchanges, compute statistics, or investigate specific packets.

Technically, files start with a four-byte signature "GMBU" which identifies the Network Monitor version 2.x format (version major 2, minor in binary-coded decimal). The header is padded to 128 bytes and includes offsets and lengths for various DATA structures such as FrameTable, CommentData, NetworkInfo, and Statistics.

Programs that open these CAP files

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

Snoop Capture File

We know that one CAP format is Snoop Capture File. We have not yet analyzed in detail what these files contain and what they are used for. We're working on it.

Ventura Publisher Caption

We know that one CAP format is Ventura Publisher Caption. We have not yet analyzed in detail what these files contain and what they are used for. We're working on it.

XCP Network Capture File

We know that one CAP format is XCP Network Capture File. We have not yet analyzed in detail what these files contain and what they are used for. We're working on it.

Programs that open these CAP files

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

Various apps that use files with this extension

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

Help us help others

File.org helps thousands of users every day, and we would love to hear from you if you have additional information about CAP file formats, example files, or compatible programs. Please use the links below or email us at submit@file.org to discuss further.