What is the difference between DNG and CR2?

CR2 is Canon's proprietary RAW format, introduced in 2004 and used until around 2018. DNG is Adobe's open Digital Negative format, based on the TIFF/EP standard. Both hold roughly the same sensor data, but DNG is documented and vendor-neutral, so more software can read it, while CR2 is tied to Canon and Adobe's decoders.

Is DNG better than CR2?

Not in image quality — they carry essentially the same sensor data. DNG wins on openness and longevity: it is a published standard with a free Adobe converter, and it is often 15–25% smaller thanks to better lossless compression. CR2 wins on being the untouched original, with all Canon-specific data intact and no extra conversion step.

Should I convert my CR2 files to DNG?

Convert if you want smaller files, a vendor-neutral archive that any future software can read, or you edit across multiple programs. Keep the CR2 originals if storage is cheap and you prefer to preserve the untampered source. A sensible compromise is to keep the original CR2 and use DNG as a working copy.

Does converting CR2 to DNG lose quality?

No, when the conversion uses lossless compression, which is the default. The pixel data is preserved bit-for-bit and stays editable. Only the optional lossy DNG mode, which is designed for smaller working files, discards information — avoid it for anything you want to keep long term.

Are DNG files smaller than CR2?

Usually yes, by around 15–25%, because DNG uses more efficient lossless compression and often stores a smaller embedded preview. The saving depends on the camera, but it is real enough that photographers with large archives convert partly to save space.

Can I open CR2 files without Canon software?

Yes. You don't need Canon's Digital Photo Professional. Adobe Camera Raw, Lightroom, Capture One, DxO and free tools like Darktable and RawTherapee all read CR2. For a quick look or to share a photo without any of those, a browser converter can decode CR2 locally and export a JPG.

DNG vs CR2: Adobe's Universal RAW vs Canon's Original

Same data, different wrapper

It's tempting to think DNG and CR2 are rival formats, but they are really two containers for the same thing: unprocessed sensor data from a camera. CR2 is Canon's proprietary original — the file the camera writes. DNG is Adobe's Digital Negative, an open format you usually arrive at by converting a CR2 (or CR3, or NEF) into it. The pixels barely change; what changes is openness, size and where the format will still open in ten years' time.

CR2: Canon's original

Introduced in 2004 with cameras like the EOS 20D and 350D, and used until roughly 2018, when Canon moved to CR3.
Proprietary but documented-ish: CR2 is based on TIFF, which is why so many RAW converters can read it, but the exact structure is Canon's.
All Canon data intact: the file stores the camera's own metadata, lens data and often a full-size embedded JPEG preview.
The untouched source: nothing has been rewritten, which some photographers consider the safest thing to keep forever.

DNG: Adobe's open standard

Released by Adobe in 2004 as a public, documented format based on TIFF/EP, with a free DNG Converter on every platform.
Vendor-neutral: Leica, Ricoh, Pentax and Apple's ProRAW write DNG natively, and any software can implement it without reverse-engineering a brand.
Better compression: lossless DNG files are typically 15–25% smaller than the equivalent CR2.
Forward-looking: because the specification is public, DNG is widely treated as the safer bet for long-term archival — software can be written to read it without permission.

Image quality: a tie, with one honest caveat

Converting CR2 to DNG with lossless compression preserves the pixel data exactly — no generation loss, no reduced editability. So for image quality the two are the same. The caveat is Canon-specific data. Some proprietary features (certain lens-correction metadata, in-camera peripheral illumination data and specific Dual Pixel information on some bodies) may not carry across perfectly, or may live only in the original. In practice that rarely affects the finished photo, but it is a genuine reason some photographers keep the CR2 as the master and treat DNG as a working copy.

Compatibility: DNG pulls ahead

Both formats are supported by the major RAW editors — Adobe Camera Raw, Lightroom, Capture One, DxO and the free Darktable and RawTherapee. But DNG has wider reach because it is an open standard: it's the format you convert to when you want a file that older or future software can read without a brand-specific update. If a camera is discontinued and its RAW support drops out of a new program, a DNG export of those files often keeps working.

Should you convert your CR2 archive to DNG?

Yes, if: storage is tight and the 15–25% saving matters; you edit across multiple programs; or you want a vendor-neutral archive unlikely to be orphaned.
No, if: storage is cheap, you shoot one brand with one editor, and you value keeping the exact camera original with all its metadata.
The middle path: keep the CR2 as the master, convert to DNG only for the files you actively edit, and always keep them in a versioned backup.

What about CR3?

If your camera is newer than about 2018, you likely have CR3 rather than CR2. It's a different container (based on the ISO Base Media File Format, similar to MP4) and is often smaller than CR2. The DNG logic is unchanged: DNG remains the vendor-neutral destination, and DNG Converter reads CR3 as well as CR2. For a quick JPG without any editing software, there are dedicated CR2 and CR3 converters, plus a general RAW to JPG tool.

How to convert CR2 (or CR3) to DNG for free

Adobe's DNG Converter is a free, standalone download for Windows and macOS — no Creative Cloud subscription required. The workflow:

Install DNG Converter and point it at a folder (it can read a memory card's folder directly).
Pick a compatibility level. A newer "Camera Raw" level is more capable; an older one is readable by more software but may omit newer features.
Leave compression at lossless — the default — unless you specifically want the smaller lossy working files.
Click Convert. Big folders take a while, because each file is re-encoded losslessly.

Lightroom can also convert to DNG on import, which is the tidy way to standardise an archive as you ingest it.

A rough size comparison

Sizes vary by camera, but a 24 MP Canon file from the CR2 era is often around 25–30 MB, and the same image as a lossless DNG usually lands around 18–24 MB. Over a library of 50,000 photos that 15–25% saving can reach hundreds of gigabytes — which is exactly the argument that convinces photographers to convert.

The bottom line

CR2 is the untouched original; DNG is the open, slightly smaller, more portable copy. Neither changes your image. Keep whichever fits your storage and backup habits, and remember that when you need to hand a photo to someone, you want a JPG exported from either one.

If you just need a usable photo, skip the debate

The DNG-versus-CR2 question only matters for archiving and editing workflows. If all you want is a photo to share, print or upload, neither RAW container is what you need — you want a JPG. The converter at the top of this page decodes CR2, CR3, DNG and other RAW formats in your browser and exports a JPG directly, with no Adobe software and no upload. See what a RAW file is if you'd like the background, or the DNG to JPG converter for the DNG-specific path.