Image MIME Reference

Share Copy URL

canon-cr3

Canon RAW 3 MIME Type Reference

image/x-canon-cr3 Released 2018 · by Canon Inc.

Canon RAW Version 3 (CR3) is a proprietary raw image format introduced by Canon in 2018 alongside the EOS M50. Moving away from the TIFF-based structure of its predecessor (CR2), CR3 is built upon the ISO Base Media File Format (ISOBMFF). It supports traditional uncompressed (lossless) raw data as well as a highly efficient compressed raw format (C-RAW), which significantly reduces file sizes with minimal impact on image quality.

Photography & Camera RAW ✦ HDR Production Ready

Copy Link Twitter LinkedIn

Technical Specifications

MIME Type

image/x-canon-cr3

Extensions

.cr3

Container

ISOBMFF (ISO/IEC 14496-12)

Compression

Lossless & Lossy (C-RAW)

Algorithms

Canon Proprietary LosslessCanon Proprietary Lossy (C-RAW)

Color Depth

14-bit (Per Channel)

Metadata

EXIF XMP ICC

Capabilities

Transparency

Animation

Progressive Loading

Alpha Channel

HDR Support

Official Specification

Aliases: image/cr3image/x-cr3

Magic Bytes & HTTP Headers

File Signature (Magic Bytes)

Copy

00 00 00 18 66 74 79 70 63 72 78 20

ASCII: \x00\x00\x00\x18ftypcrx

HTTP Headers

Content-Type: image/x-canon-cr3

HTML Accept Attribute

accept="image/x-canon-cr3, .cr3"

Browser Support Matrix

Browser	Status	Min Version
Chrome	Not Supported	—
Firefox	Not Supported	—
Safari	Not Supported	—
Edge	Not Supported	—
Internet Explorer	Not Supported	Legacy

Advantages & Limitations

Advantages

• Maintains 14-bit uncompressed sensor data, offering massive flexibility for recovering shadows and highlights in post-production
• The new C-RAW format offers roughly 40% smaller file sizes than uncompressed raw with virtually indistinguishable quality loss
• Utilizes the modern and extensible ISOBMFF container, moving away from archaic TIFF limitations

Limitations

• Being a proprietary format, it requires frequent software updates to third-party editing tools (like Lightroom or Capture One) every time a new camera model is released
• Completely unsupported in web browsers and standard operating system image viewers without specialized raw codecs
• Larger file sizes than in-camera JPEGs, requiring more storage space and processing power

Developer Code Snippets

Python Node.js Go PHP

Copy

import magic
print(magic.from_file('photo.cr3', mime=True)) # Outputs 'image/x-canon-cr3' or 'video/mp4' due to ISOBMFF structure

const FileType = require('file-type');
const type = await FileType.fromFile('photo.cr3');
console.log(type.mime); // image/x-canon-cr3

import "net/http"

mimeType := http.DetectContentType(fileBytes)
fmt.Println(mimeType) // Note: Standard net/http may default to video/mp4 due to the ftyp header

$mime = mime_content_type('photo.cr3');
echo $mime; // image/x-canon-cr3 (requires updated magic file)

File Detection Steps

How to programmatically detect a image/x-canon-cr3 file by reading its raw bytes:

1. 1 Check for the ISOBMFF 'ftyp' box starting at byte 4
2. 2 Verify that the major brand identifier at byte 8 is 'crx ' (Hex: 63 72 78 20)

Software Support

A

Adobe Lightroom Classic / CC

C

Canon Digital Photo Professional (DPP)

C

Capture One

R

RawTherapee

Free Online Tools for canon-cr3

Free Image Resizer

Editor

Resize, scale, crop, and modify dimensions for any photo or graphic.

Open Tool

Image Metadata Remover

Privacy

Clean EXIF, camera, lens, and location tags from your photos.

Open Tool

WebP to JPG Converter

Universal

Convert modern web images to universal high-compatibility JPG.

Open Tool

Compress WebP Images

Optimizer

Reduce image file sizes for faster web performance.

Open Tool

canon-cr3 Format Comparisons

Canon-CR2 vs canon-cr3 canon-cr3 vs Canon-CRW canon-cr3 vs DNG canon-cr3 vs Nikon-NEF canon-cr3 vs Sony-ARW canon-cr3 vs HEIC canon-cr3 vs WebP canon-cr3 vs JPEG canon-cr3 vs PNG AVIF vs canon-cr3 canon-cr3 vs GIF canon-cr3 vs SVG canon-cr3 vs TIFF BMP vs canon-cr3 canon-cr3 vs JXL

View all format comparisons

Share & Embed

Markdown Badge

[![canon-cr3 Format](https://freewebptojpg.com/mime/image/canon-cr3/badge.svg)](https://freewebptojpg.com/mime/image/canon-cr3)

Interactive iframe Widget

<iframe src="https://freewebptojpg.com/mime/image/canon-cr3/embed" width="100%" height="280" style="border:1px solid #cbd5e1;border-radius:8px;" title="canon-cr3 Specs"></iframe>

JSON API

All data on this page is available as a free, open JSON API. Use it in your project, documentation, or tooling.

GET https://freewebptojpg.com/mime/image/canon-cr3.json Copy URL Open JSON

Free to use

No auth required

CORS enabled

Use from any domain

Cached 24h

Cache-Control headers set

Frequently Asked Questions

What is the magic byte for image/x-canon-cr3?

Because CR3 is based on the ISOBMFF standard (like MP4), it begins with a box size followed by the 'ftyp' atom. A typical CR3 file starts with the hex sequence 00 00 00 18 66 74 79 70 63 72 78 20, which translates to the ASCII string '....ftypcrx '.

Is image/x-canon-cr3 natively supported in web browsers?

No. CR3 is a proprietary raw camera format containing unprocessed sensor data. It must be processed and converted to a standard format like JPEG, PNG, or WebP to be viewed in a web browser.

What is the difference between CR2 and CR3?

CR2 is based on the TIFF file structure, while CR3 is based on the modern ISO Base Media File Format. Additionally, CR3 introduces C-RAW, a lossy compression option that reduces file sizes by roughly 40% while maintaining the flexibility of raw editing.

Related Formats

Canon-CR2 Canon-CRW DNG Nikon-NEF Sony-ARW