What is a RAW file, and why won't my CR2 or NEF photos open?

You are back from a trip and put the camera's memory card into the computer. The folder holds hundreds of files, but their names end in .CR2, .NEF or .ARW; double-clicking does nothing, or the computer asks which program it should use. Copied to your phone, they do not appear in the gallery, and your messaging app will not attach them as photos.

Your files are fine. The camera saved them in a format called RAW: not a finished photo, but the raw reading taken from the camera's sensor. Below we explain what that reading is, which extension belongs to which brand, and the two ways to turn the pictures into JPGs you can share.

Telling the camera brand from the extension

RAW is not one format but a family of them; every manufacturer uses its own extension. The extension is the set of letters after the last dot in the file name. If Windows hides them, open File Explorer and turn on View, then Show, then File name extensions. The table shows both the brand and whether this site's RAW to JPG tool supports the format.

Why a RAW file does not open like a photo

A JPG is a finished product: the camera has worked out the colours, made white look white, set the sharpness and compressed the result. Every phone and every browser can read it. A RAW file is the stage before all of that; it records how much light each point of the sensor received, but it has not yet been turned into a colour picture.

In other words, a RAW file is like an undeveloped film negative. You cannot put a negative in an album; it has to be developed and printed first. A RAW file likewise needs a program to process it into an image, and because every manufacturer records things differently, the program has to know that brand. Galleries and sharing apps do not take on that job, which is why your files do not show up there.

There are really two things inside the file

Most cameras also tuck a ready-made JPEG inside the RAW file. It is the picture you look at on the camera's screen after taking the shot, with the camera's colour settings already applied. Taking that ready-made image out and processing the raw record from scratch are two different routes, with different results.

The quick route: taking out the JPEG inside

If you only want to show the photos, send them to family or upload them somewhere, there is no need to process the raw record. The RAW to JPG tool searches the file for ready-made JPEGs, picks the one with the most pixels and hands it to you as a separate file without touching it. Because nothing is recompressed, the quality is exactly what the camera produced, and the colours are the ones you saw on the camera's screen.

The result line states the pixel size and megapixels of each extracted image. Always glance at it: some cameras store only a small preview rather than a full-size one. If it is below 2 megapixels, the tool says so separately; that is enough for a screen but too little for a print. Canon's CR3 and Fujifilm's RAF files are not among the formats the tool supports; use the adjustable route below for those.

At the camera's full resolution the extracted JPGs can run to several megabytes each. If they need to fit in an email or an upload form, shrink the longest edge and set the quality in the Image Compressor.

The adjustable route: processing the raw record in software

Brightening a shot that came out too dark or correcting colours that drifted towards yellow can really only be done from the raw record; the ready-made JPEG leaves far less room. For that you need a program that understands RAW.

On Windows, open the Microsoft Store and search for "Raw Image Extension". Once Microsoft's free add-on is installed, File Explorer shows thumbnails of RAW files and the Photos app opens them. A Mac recognises the RAW formats of many cameras out of the box, and Apple publishes the list of supported models on its support site; simply double-clicking the file is the quickest test. Every major manufacturer also offers free software of its own: Digital Photo Professional for Canon, NX Studio for Nikon, Imaging Edge for Sony. These programs process the raw record and save a new JPG with the settings you choose.

Portrait shots, and a setting for next time

When you shoot with the camera held upright, the camera saves the picture on its side and keeps the orientation in a separate note. In its default setting, the RAW to JPG tool adds that note to the extracted JPG without rewriting the pixels, so galleries and browsers show the photo upright. If an older program or an upload form still shows it sideways, re-save the photo as a JPG with Change the Format of an Image; that tool writes the picture the way it appears, upright.

If you would rather not go through this every time, find the image quality or file format setting in your camera's menu and choose RAW+JPEG instead of RAW. The camera then saves every shot twice: a JPG ready to share and a RAW file in case you want to adjust it later. It takes more space on the card, but your shareable photos are ready the moment you copy them over.

Frequently asked questions

Can I delete the RAW files once I have the JPGs?

You can, but you give something up: the freedom to rework exposure and colour later exists only in the raw record. If you have the space, keeping the RAW files of important shoots on an external drive is the safer choice.

Why are RAW files so large?

The raw record keeps the reading of every point on the sensor without the trimming and compression a JPG applies. On top of that it carries the ready-made JPEG preview. That is why the RAW file of a shot takes up several times the space of its JPG version.

Should I shoot RAW or JPEG?

If you mostly share your photos as they come, JPEG is enough and makes life easier. If you shoot in difficult light and like to make corrections afterwards, RAW+JPEG is the most comfortable choice: you get a ready file and the raw record.

Why did my DNG file not open?

DNG is a shared container, so what is inside depends on whoever created the file. If no ready-made JPEG was stored in it, the tool finds nothing to extract and says so plainly; if only a small preview was stored, you get a small JPG and a warning next to its size. Either way, full size needs a program that can read RAW.

Last updated: October 12, 2026