Open EXR and HDR files on Windows — without a plugin

Double-click an .exr and look at it. No plugin to hunt down, no codec pack, no installer, no subscription — the decoders are compiled into one free 9.7 MB executable.

Windows itself cannot open .exr or .hdr, and the usual answers are "buy Photoshop", "install a plugin for IrfanView", or "convert it first". QuickImageViewer decodes them itself, along with .qoi and the .ppm / .pgm / .pbm family. Download one file, run it, done.

The formats it decodes on its own

FormatExtensionsHow
OpenEXR .exr tinyexr, compiled in. Reinhard tone-map and gamma 2.2 for display
Radiance HDR .hdr Own decoder — RGBE with adaptive run-length, same tone-map
QOI .qoi Own decoder. Lossless, and very fast to read
PNM .ppm .pgm .pbm Own decoder — P1 to P6, up to 16-bit maxval
SVG .svg resvg, on a background thread so a complex file cannot stall the window

None of those need anything installed. They are in the executable you downloaded.

Why these formats are awkward everywhere else

.exr and .hdr come out of 3D renderers, compositors and bracketed camera work. They hold far more brightness range than a monitor can show, which is exactly why they exist — and exactly why an ordinary picture viewer cannot simply put one on screen.

So most viewers do not try, and Windows Photos will not open them at all. You end up launching a compositor to answer "which render is this", which is a slow way to look at a picture.

What it does with the extra range

It tone-maps. The image is mapped down with a Reinhard tone-map and gamma 2.2, which is a reasonable, neutral way to make a high-range image look like the photograph it represents.

It is a viewer, not a grading tool. There is no exposure slider, no curve, and no attempt to replace Nuke, Blender or Photoshop. It answers "what is in this file" in the time it takes to let go of the mouse button. If you need to work on the image, open it in the thing you were going to open it in anyway.

Two things that genuinely do need an extension

Being straight about this, because a page that overstates what it opens is a page you find out about at the worst moment:

AVIF works natively on Windows 11, and JPEG XL on Windows 11 24H2 and later. The full format table →

Questions

What does it cost?

Nothing. QuickImageViewer is free and open source under the AGPL — no advertising, no telemetry, nothing to buy, no account.

Do I have to install it?

No. One executable, no installer, no Visual C++ Redistributable. To remove it, delete the file. It does keep its settings in the registry by default, so a copy carried on a USB stick leaves that much behind on each machine — pass -config with a path and it uses an .ini beside itself instead, and touches nothing else.

Can I make it the default for .exr files?

Yes, through Windows itself: right-click an .exr, choose Open with → Choose another app, point it at the executable and tick Always use this app. Windows remembers it from then on.