What Is an EXR File?

This article describes what an EXR file is and how to open one or convert one to a different image format.

What Is an EXR File?

A file with the EXR file extension is an OpenEXR bitmap file. It's an open-source high-dynamic-range image file format created by the Industrial Light & Magic visual effects company.

Files in this format are used by various photo editing, visual effects, and animation programs because they can store high-quality images, can be comprised of lossless or lossy compression, support multiple layers, and hold a high luminance range and color.

More information on this format can be seen on the official OpenEXR website.

How to Open an EXR File

The fastest way to view an EXR image is online, using OpenHDR Viewer. Another free program that supports the format is the GIMP image editor.

Other ways include using Adobe Photoshop or Adobe After Effects. The now-discontinued Adobe SpeedGrade works, too, but since it's no longer available, you might be able to find some of its functions in the Lumetri color tools in Adobe Premiere Pro.

ColorStrokes and advanced imaging programs should also be able to open EXR files.

How to Convert an EXR File

AConvert.com is an example of an online tool that supports this format. It can save your file to JPG, PNG, TIFF, GIF, and many other formats. This website can also resize it before the conversion.

You might also be able to convert an EXR file using one of the programs from above that can open the file, but a dedicated file converter is much quicker and doesn't need to be installed to your computer before you use it.

Still Can't Open It?

If you can't get your file to open in any of the programs mentioned above, make sure you're reading the file extension correctly. Some files might look like they could be related to EXR files because the file extensions are similar.

Some examples include EXE, EXO, EX4, ERF, and EXD files. While they do share some of the same letters, the formats aren't necessarily related and therefore probably can't be opened with the same tools.

If you don't really have an EXR file, research the file extension that's at the end of your file so that you can learn more about the format it's in and, hopefully, find a compatible viewer or converter.

More Information on EXR Files

The OpenEXR bitmap file format was created in 1999 and released to the public for the first time in 2003. You can monitor the latest versions of the format on the Academy Software Foundation's GitHub: OpenEXR Release Notes.

Since version 1.3.0 (released June 2006), the OpenEXR format supports multithreading reading/writing, which improves performance for CPUs with multiple cores.

This file format supports several compression schemes, including PIZ, ZIP, ZIPS, PXR24, B44, and B44A.

See the Technical Introduction to OpenEXR document from OpenEXR's website for more information on not only EXR compression but also a closer look at the format's features, file structure, and lots of other super specific details.