C1S file format description

Many people share .c1s files without attaching instructions on how to use it. Yet it isn’t evident for everyone which program a .c1s file can be edited, converted or printed with. On this page, we try to provide assistance for handling .c1s files.

1 filename extension(s) found in our database.

.c1s - Capture One Photo Cache Data

The C1S data files are related to Capture One. The C1S file is a Capture One Photo Cache Data. Capture One is a raw converter and photo editor that supports raw formats from more than 250 cameras and digital backs.

Capture One
Data files
- / -
Capture One Photo Cache Data related extensions:
RFM Instrument Line Shape File
BRE U-value Calculator Data
Adobe Photoshop Menu Customization Data
MTFLOW Geometry Data
Watershed Modeling System GHM Data

Naturally, other applications may also use the .c1s file extension. Even harmful programs can create .c1s files. Be especially cautious with .c1s files coming from an unknown source!

Can't open a .c1s file?

When you double-click a file to open it, Windows examines the filename extension. If Windows recognizes the filename extension, it opens the file in the program that is associated with that filename extension. When Windows does not recognize a filename extension, you receive the following message:

Windows can't open this file:


To open this file, Windows needs to know what program you want to use to open it. Windows can go online to look it up automatically, or you can manually select one from a list of programs that are installed on your computer.

To avoid this error, you need to set the file association correctly.

The .c1s file extension is often given incorrectly!

According to the searches on our site, these misspellings were the most common in the past year:

c1, c1w, c1z, cls, cqs, cs, cs1, cws, x1s

Is it possible that the filename extension is misspelled?

Similar file extensions in our database:

CLASS Group Abbreviation
ChordWizard Songtrix Song
Visual Basic Class Module
ArcInfo Geocoding Classification Data
Java Class Data
ClarisWorks Template

Operating systems

DataTypes.net currently supports the following operating systems:

Windows XP/Vista, Windows 7/8/10, Windows 11, CentOS, Debian GNU/Linux, Ubuntu Linux, FreeBSD, macOS, Mac OS X, iOS, Android

If you find the information on this page useful, please feel free to link to this page.


If you have useful information about the .c1s file format, then write to us!

DataTypes.net >> C1S file