Can I convert Radiance HDR to PPM / PNM on iPhone, Android, Mac or Windows?

Yes. ConvertPixels works in Safari, Chrome, Edge and Firefox on any device, so you can convert Radiance HDR to PPM / PNM on your phone or computer without installing an app.

Is there a free HDR to PPM converter with no sign-up?

Yes, this one. Converting HDR to PPM on ConvertPixels is free, with no sign-up, no watermark and no daily cap. Convert up to 30 files per batch, each up to 50 MB.

Can I convert HDR to PPM without losing quality?

Yes. PPM is a lossless format, so your converted file is pixel-for-pixel the same as the HDR. (It can't add back detail the original never had.)

Can I batch convert HDR to PPM?

Yes. Add up to 30 HDR files and convert them in one batch. You can even choose a different output format for individual files, then download them separately or together as a ZIP.

Is it safe to upload HDR files to ConvertPixels?

Yes. Uploads use an encrypted connection and are processed automatically - nobody views them. Your originals are deleted straight after conversion and the results within an hour, or instantly if you click "Delete from server now".

Convert

Radiance HDR to PPM / PNM Converter

Convert Radiance HDR images to PPM / PNM online in seconds - free, with no sign-up and no watermark. Batch convert up to 30 files and download them together as a ZIP.

Free
No sign-up
No watermark
Private by design

Choose filesor drag and drop files hereUp to 30 files · 50 MB each

Image Converter

How to use it

1
Drop your Radiance HDR files onto the converter
2
Press Convert to turn them into PPM / PNM
3
Download your PPM / PNM images one by one or as a ZIP

Radiance HDR to PPM / PNM

Why convert HDR to PPM?

HDR and PPM are both lossless formats. PPM is the usual choice for simple uncompressed images for scientific and developer tools.

Where PPM works best

PPM is ideal for simple uncompressed images for scientific and developer tools. Converting gives you a file that works in the apps and websites that ask for PPM.

Radiance HDR vs PPM / PNM: what's the difference?

Property	Radiance HDR	PPM / PNM
Compression type	Lossless (exact pixels, larger files)	Lossless (exact pixels, larger files)
Transparent background	No	No
Animation	No	No
Where it opens	None	None
Used for	3D lighting (HDRI environment maps) and visual effects	Simple uncompressed images for scientific and developer tools

What is an Radiance HDR file?

Radiance HDR (.hdr) is a high dynamic range format that stores the real brightness of a scene, far beyond what a normal photo can hold. It's used for HDRI environment maps that light 3D scenes, and in visual effects.

HDR files look flat or blown out in ordinary viewers because screens can't show that range directly - they need tone mapping, which converting to JPG or PNG applies.

How to open an Radiance HDR file

Photoshop, GIMP, Blender, Affinity Photo and most 3D software open .hdr files. Mac Preview shows a basic preview. Convert to JPG or PNG to get a viewable, shareable image.

Extensions: .hdr, .pic
Range: High dynamic range (32-bit float)
Best for: HDRI lighting, visual effects
Also called: RGBE

What is a PPM / PNM file?

PPM, PGM, PBM and PNM are the Netpbm formats: deliberately simple, uncompressed image files from the 1980s. They store pixels as plain numbers, which makes them easy for programs to read and write.

You'll mostly meet them in scientific computing, image-processing scripts and developer tools - rarely in everyday use.

How to open a PPM / PNM file

GIMP, IrfanView, XnView and Photoshop open Netpbm files, as do Linux image viewers. Windows Photos and browsers can't, so convert to PNG for a lossless, much smaller copy.

Extensions: .ppm, .pgm, .pbm, .pnm
Compression: None
Best for: Scientific and developer tools
Family: Netpbm