.C4P file extension
To open .C4P files on Windows, install or use an existing Clonk installation and open/load the player profile from within the game (player management/profile selection).
To open a .C4P file, use a Clonk game installation (the game can load player files). If you only need to inspect its contents, treat it as a Clonk “group” container associated with the MIME type application/vnd.clonk.c4group and open it with tools that can read Clonk group files.
Last updated: April 29, 2026 · Reviewed by Julian Stricker
Open on your device
Choose your operating system for a dedicated step-by-step opening guide.
How to open .C4P files
Use these platform-specific instructions to open .C4P files safely.
Windows
- Install or use an existing Clonk installation and open/load the player profile from within the game (player management/profile selection).
- If you received the file separately, place it into the location your Clonk installation uses for player files and then select it in-game.
- If needed, start Clonk using a command-line option that accepts a .c4p player file (see Clonk command-line documentation).
Mac
- Use a Clonk installation that supports player profiles and load/select the .c4p file from within the game.
- If the file was downloaded, move it into the game’s expected player/profile folder and then select it in-game.
Linux
- Use a Clonk installation and load/select the player profile from within the game.
- If your desktop environment identifies it by MIME type, it may appear as application/vnd.clonk.c4group; open it with the Clonk app or a Clonk group-capable tool if installed.
- For advanced use, launch Clonk from the terminal and pass the .c4p file using the documented command-line parameters.
iOS
- There is no common native iOS support for Clonk player/group files; transfer the .c4p to a desktop (Windows/macOS/Linux) with Clonk installed to open it.
Android
- There is no common native Android support for Clonk player/group files; transfer the .c4p to a desktop (Windows/macOS/Linux) with Clonk installed to open it.
Security notes
- .C4P is a group/container format used by a game ecosystem; treat files from untrusted sources cautiously because container formats can be used to deliver unexpected content that triggers vulnerabilities in the consuming application.
- Prefer opening .c4p files only in the intended Clonk environment (or trusted Clonk group tools), and keep the game/tool updated before importing player files from others.
- Do not rename a suspicious file to .c4p to force it to open; verify it is actually a Clonk player/group file before loading it into Clonk.
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Can't open this file?
These are the most common causes and fixes when .C4P files fail to open.
Common reasons
- The file opens in the wrong app or shows as an unknown file type
- Clonk does not recognize the .C4P player profile
- Cannot open on mobile (iOS/Android)
Fix steps
- Open the file from within Clonk instead of double-clicking it in the file manager.
- On Linux, check file associations for application/vnd.clonk.c4group and set Clonk (or a Clonk group-capable tool) as the default if available.
OS-specific troubleshooting
What is a .C4P file?
.C4P is a Clonk “player file” that contains personal player data such as settings, score, and crew information, and may include a portrait. Clonk stores many resources in compressed “group” files, and .c4p is one of the extensions used within this group-based file system. The registered vendor MIME type commonly associated with these group-based Clonk files is application/vnd.clonk.c4group.
Background
In the Clonk game ecosystem, .c4p is the standard extension for player profiles. These files hold player-specific information (for example personal settings and scores) and may include additional assets such as a portrait.
Clonk data is often packaged in “group” files, which are essentially containers used by the engine to store multiple related resources together. Because .c4p follows this group-based approach, it may not behave like a simple single-document file in general-purpose apps.
Practically, the easiest way to use a .c4p file is within Clonk itself—e.g., placing it where the game expects player files or referencing it when starting the game. Clonk also supports passing player files via command-line parameters, which can help when troubleshooting or selecting a specific player profile.
Common MIME types: application/vnd.clonk.c4group
Further reading
Authoritative resources for more details on the .C4P format.
- Clonk Resource Documentation: File types (.c4p player files)
- Clonk Resource Documentation: Command line parameters (player files)
- IANA Media Types Registry (index)
- IANA Media Types Registry entry: application/vnd.clonk.c4group
- freedesktop.org Shared MIME-info Database specification (how MIME types and extensions are handled on Linux desktops)
- Cisco Crosswork Optimization Engine Open Source Used In (MIME mapping table referencing application/vnd.clonk.c4group and extensions including c4p)
Common .C4P issues
The file opens in the wrong app or shows as an unknown file type
Many systems do not recognize .c4p as a user-document format. On Linux desktops it may be associated with the vendor MIME type for Clonk group files (application/vnd.clonk.c4group), but the correct handler may not be installed.
- Open the file from within Clonk instead of double-clicking it in the file manager.
- On Linux, check file associations for application/vnd.clonk.c4group and set Clonk (or a Clonk group-capable tool) as the default if available.
Clonk does not recognize the .C4P player profile
This can happen if the file is placed in the wrong folder, is from a different Clonk setup, or is incomplete/corrupted.
- Confirm the file is in the correct player/profile directory expected by your Clonk installation.
- Try selecting the player file explicitly using Clonk’s command-line parameters (if applicable).
- Re-download or re-copy the file to ensure it was transferred completely.
Cannot open on mobile (iOS/Android)
.c4p is a game-specific container used by Clonk and is not typically supported by mobile document viewers.
- Transfer the file to a desktop computer and open it with a Clonk installation.
- If you only need to share it, keep it as-is and avoid renaming the extension.
FAQ
What is a .C4P file used for?
In Clonk, .c4p is a player file that stores personal settings, score, crew information, and possibly a portrait.
Is .C4P just an archive (container) file?
It is part of Clonk’s group-based data system (a container concept used by the engine). Even if it behaves like a container, it is meant to be used by Clonk as a player profile file.
What MIME type is associated with .C4P?
A commonly associated, officially registered vendor MIME type is application/vnd.clonk.c4group.
Can I convert a .C4P file by renaming the extension?
No. Renaming only changes the filename; it does not change the underlying format. Use Clonk’s own functions or workflows if you need to move or recreate a player profile.
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