A CR3 file is an image created by select Canon digital cameras, such as the Canon EOS M50. It may store uncompressed RAW image data exactly how it was captured by the CCD or compressed RAW (C-RAW) image data depending on the camera setting selected. CR3 files were introduced in 2018 with the release of the Canon EOS M50, replacing .CR2 files.
The CR3 format is based on the ISO Base Media File Format, and includes custom tags and the crx codec, which supports lossless RAW and lossy C-RAW compressions. If saved with lossy C-RAW compression, the image is roughly 40% smaller in size with minimal differences in image quality.
The Canon EOS M50 comes with the Digic 8 processor, which allows it to capture images in the CR3 format. Earlier versions of Canon digital cameras used the .CRW and CR2 format. The CRW format is based on the Camera Image File Format (CIFF) and the CR2 format is based on the TIFF specification.
NOTE: CR3 files can be opened in Adobe Lightroom (version 2.0 or later) or Adobe Lightroom Classic (version 8.0 or later) with the Adobe Camera Raw plugin (version 11.0 or later) installed. You can also open CR3 files in Canon Digital Photo Professional and convert them to other formats or in Canon Digital Photo Professional Express on an iPad and convert them to .JPG files.