C3P File

What are C3P files and how to open them

Are you having problems opening a C3P 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 C3P files.

What is a C3P file?

A .C3P file is a Construct 3 Project/Package file.

A Construct 3 Project/Package file stores the full structure and content of a user's Construct 3 project in a single, portable archive. It is created by Construct 3 when a project is saved as a "single file" project. It bundles together project metadata, layouts, event sheets, images, scripts, audio, fonts, icons and other assets.

Construct 3 reads and writes these files; they are the native format for sharing, backing up, or moving projects. A developer working within Construct 3 exports the project into this format, and can later reopen it to continue editing - either in the browser, desktop-app-capable version, or by converting a folder-based project back into it. Construct 3 also supports using folder-based project structure instead of a single-file archive for workflows such as version control or external editor editing.

Technically, the file is a standard ZIP archive renamed to use the .c3p extension, often called a zipped folder project. Internally there is a file project.c3proj in JSON format that lists and indexes all resources. The archive also contains subfolders such as layouts, eventSheets, objectTypes, images, sounds, fonts etc., plus UI state files and texture images in formats like PNG. Individuals files can be extracted by renaming the archive to .zip.

Byte-pattern signatures include the standard ZIP header "PK 03 04" at offset 0. Other identifying internal names in the archive are "PROJECT.UISTATE.JSON", "PROJECT.C3PROJ", "EVENTSHEETS", "LAYOUTS", "OBJECTTYPES", various PNG image size suffixes (‐16.PNG, ‐32.PNG, ‐128.PNG, ‐256.PNG), and PNG chunk markers such as IHDR, IDAT, IEND.

How to open C3P files

Important: Different programs may use files with the C3P file extension for different purposes, so unless you are sure which format your C3P file is, you may need to try a few different programs.

While we have not verified the app ourselves yet, our users have suggested a single C3P opener which you will find listed below.

Last updated: August 25, 2026

Various apps that use files with this extension

These apps are known to open certain types of C3P files. Remember, different programs may use C3P 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 C3P file formats, example files, or compatible programs. Please use the links below or email us at submit@file.org to discuss further.