HDR to ICON Converter
FileFlip converts HDR to ICON entirely inside your browser, using ImageMagick compiled to WebAssembly. The file is never uploaded to a server: it is read off your disk, converted on your own machine, and saved back by the browser. That means no file-size limit, no queue and no account.
How do I convert an HDR file to ICON?#
- Drop your HDR file onto the converter at the top of this page, or click it to pick one from your computer. You can add as many as you like.
- Leave the target set to ICON and the conversion starts on its own. FileFlip downloads 14.1 MB of WebAssembly the first time and nothing after that, then runs ImageMagick on your own machine.
- Save the ICON file. Your browser writes it straight to your downloads folder, because there was never a server holding it.
Does converting HDR to ICON lose quality?#
No. Converting HDR to ICON writes the data out again without discarding any of it, so nothing that was in the HDR file is lost on the way. What changes is the size of the file, not what is inside it.
Is it safe to convert HDR files online?#
Yes, because nothing is uploaded. FileFlip converts HDR files inside the browser tab you already have open, using WebAssembly builds of the same engines a desktop converter would install. Your file is read from your own disk into the page's memory, and no request carrying it is ever made.
You do not have to take that on trust. Open your browser's network panel, run a conversion, and you will see the engine come down and your file go nowhere. There is no upload, no server-side copy, no retention window, and no account tied to what you converted.
How FileFlip works lists every engine, its version and its download size, and shows how to check for yourself that nothing leaves your machine.
What HDR to ICON actually does to the file#
Converting HDR to ICON runs on ImageMagick, downloads 14.1 MB of WebAssembly the first time and nothing after that, writes the data out again without discarding any of it.
| Engine | ImageMagick |
|---|---|
| Conversion path | One step: HDR → ICON |
| Downloaded to your browser | 14.1 MB, once, then cached by your browser |
| Quality | Lossless |
| You get back | One file |
| Where it runs | In a background worker, so the page stays responsive |
What is an HDR file?#
An HDR file stores a high-dynamic-range raster image using Radiance's RGBE encoding, which packs red, green and blue mantissas with one shared exponent per pixel so a scene can hold a far wider range of brightness than a standard 8-bit image.
Reach for HDR when you need a compact high-dynamic-range environment map or lighting reference that most 3D tools and renderers can read without a plugin.
Convert HDR to OpenEXR when a VFX pipeline needs true floating-point precision, an alpha channel or multiple layers in one file, or convert it to JPEG or PNG once the image has been tone-mapped for a normal display.
What is an ICON file?#
ICON is ImageMagick's alternate name for the ICO format, the container Windows uses for small multi-resolution images shown as application, file and shortcut icons, so a file written as ICON is the same Windows icon container as one written as ICO.
Use ICON, or the equivalent ICO, for Windows application icons, favicons and shortcut images, where the file needs to offer several sizes in one container.
Convert to PNG when a single-resolution image is needed for general use, since most software outside Windows icon contexts doesn't expect an ICO/ICON container.
HDR to ICON questions people ask#
What is an HDR file used for?
An HDR file most often stores an environment map or lighting reference for 3D rendering, since Radiance's RGBE encoding was built for the Radiance lighting-simulation software. Photographers also use the .hdr extension for panoramas merged from several exposures, before tone-mapping the result down to a normal image.
Is an HDR file the same as an iPhone or camera 'HDR photo'?
No. A phone's HDR mode blends several exposures and saves an ordinary JPEG or HEIC, while an HDR file with the .hdr extension is a Radiance RGBE file that keeps the full brightness range rather than compressing it into 8 bits. The two share a name but not a file format.
What's the difference between HDR and OpenEXR?
HDR (Radiance RGBE) packs each pixel into 32 bits with an 8-bit mantissa per channel and a shared exponent, while OpenEXR stores true 16- or 32-bit floating-point values per channel, supports an alpha channel, and can hold multiple image layers in one file. OpenEXR has mostly replaced HDR in VFX compositing, though HDR remains common for HDRI environment maps because of its smaller size and long-standing tool support.
What is the difference between ICON and ICO?
There isn't one. ICON is ImageMagick's alternate name for its ICO coder, so a file written as ICON is the same Windows icon container as one written as ICO.