Image Format Comparison

EXR vs PNG — HDR Float vs Lossless Integer

EXR (OpenEXR) is the high-dynamic-range image format used in film VFX, 3D rendering, and gaming. It stores 32-bit floating-point values, capturing the full luminance range of real-world scenes. PNG is the standard 8/16-bit lossless web image format. They serve completely different purposes: EXR for high-fidelity production; PNG for distribution.

EXRvsPNG

Quick Verdict

Use EXR when…

Use EXR for VFX compositing, 3D render outputs, HDR photography masters, and any workflow where you need to preserve scene-referred linear floating-point data for grading.

Use PNG when…

Use PNG for web, UI graphics, screenshots, and any context where the recipient expects a standard image. PNG is universal; EXR requires specialized tools to view.

EXR vs PNG: Feature Comparison

Feature	EXR	PNG
Bit depth	16/32-bit float	8/16-bit integer
HDR support	Native — designed for it	16-bit PNG approximates HDR
Color spaces	Linear, scene-referred	sRGB (typically)
Compression	ZIP, PIZ, ZIPS, RLE (lossless or lossy)	DEFLATE (lossless)
Browser support	None	Universal
Production use	VFX, 3D, gaming	Web, UI, all general use

When EXR wins

✓Bit depth: 16/32-bit float
✓HDR support: Native — designed for it
✓Color spaces: Linear, scene-referred

When PNG wins

✓Bit depth: 8/16-bit integer
✓HDR support: 16-bit PNG approximates HDR
✓Color spaces: sRGB (typically)

Frequently asked questions

Can I display an EXR on a website?

Not directly — no browser supports EXR. Convert to PNG with tone mapping for display: `oiiotool input.exr -tonemap aces -o output.png` (using OpenImageIO). The result is a tone-mapped 8-bit PNG that approximates the HDR scene on standard displays.

Is EXR better than PNG for screenshots?

No — for screenshots, PNG is the right format. EXR is overkill (32-bit float for what's already 8-bit display data). EXR's value is for content that has more range than 8-bit can represent: VFX renders, RAW photo conversions, scientific imagery.