HDR to JPG Converter
A .hdr file is usually a Radiance picture used for lighting, panoramas and environment maps, and ordinary programs often cannot show it. This converter reads the file, tone-maps its wide brightness range down to eight bits and saves a JPG on your own device. It is a quick way to see what is in the file.
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How to convert HDR to JPG
- Add your HDR files by dropping them, clicking the drop zone or pasting.
- The output format is already set to JPG. Adjust quality or size if you need to.
- Press Convert and compare the original and new size for each file.
- Download each file or all of them as a ZIP.
When to convert, and when not to
- You want to preview an environment map or lighting image before using it.
- You need a normal picture of a .hdr file for a document or a chat.
- You will keep the .hdr as the real asset for rendering.
- Do not use the JPG as a light source in a 3D scene; it has lost the extra brightness.
What changes
- The wide brightness range is tone-mapped to a range a JPG can hold.
- If the file declares a gamma value in its header, the converter respects it and does not apply a second curve.
- Only the standard RGBE form is read. XYZE files and rotated layouts give a clear message.
- JPG is lossy and has no transparency; the quality slider balances size and detail.
- Header comments and metadata are not carried across.
What is inside a Radiance file
Radiance .hdr files store each pixel as red, green and blue values plus a shared exponent. That lets them record brightness far beyond what a monitor can show, which is why they are common for lighting. A JPG has no room for that, so the converter has to choose how to fit the range.
How the converter fits the range
It scales the values so that the picture looks balanced and then maps them to eight bits per channel. Where the header says the data already carries a gamma curve, the extra curve is skipped so the picture is not washed out. The outcome is a sensible preview rather than a calibrated reproduction, and the same file can look different in other software.
Panoramas and environment maps
Many .hdr files are wide panoramas that look stretched when seen flat. That is normal: they are meant to be wrapped around a scene. The JPG will show the same flat layout. If you only want to know what is in the file, that is enough.
Files that will not open
A clear message appears for XYZE files, which use a different colour space, and for layouts that are rotated relative to the usual order. For those, open the file in a 3D or imaging tool that supports them, or ask for an export in the standard form.
Judging the result
Open the JPG next to the original in your 3D or imaging software at the same size. The sun, bright windows and other very bright spots will look duller in the JPG, because their extra brightness is gone. That is expected. What you are checking is the overall layout, colour and mood of the environment. Zoom in on one area before you decide, because small details can look different at different sizes. If the picture looks right, the file is what you thought it was, and you can go back to the .hdr for rendering.
Privacy: your files stay on your device
- The tool decodes, resizes and encodes your pictures with your browser. The files are never sent to a server.
- To check it yourself: open the browser developer tools (F12), open the Network tab, convert a file, and look for any request that carries your image. You will see none.
Frequently asked questions
Why does my JPG look flatter than the HDR in my 3D program?
A 3D program uses the full brightness range for lighting. The JPG holds only eight bits per channel, so it is a tone-mapped view of the file.
Can I keep the lighting data?
No. Keep the .hdr file for rendering and use the JPG only as a picture of it.
Why is my panorama stretched?
Environment maps are stored in a flat layout meant to wrap around a scene. The converter does not reproject them.
What does the message about XYZE mean?
Some Radiance files use a different colour encoding. This converter reads the standard RGBE form only.
Which output should I choose for a quick look?
JPG gives a small file. Choose PNG in the options if you want to avoid compression artefacts in smooth skies.
Why are the bright spots dull in the JPG?
Very bright areas such as the sun hold values far above white in the .hdr. A JPG cannot store them, so they are compressed into the top of the range.