HDR Converter
FileFlip converts HDR files into 61 other formats entirely inside your browser, using ImageMagick, MuPDF and Pandoc compiled to WebAssembly. The HDR file is never uploaded to a server: it is read off your disk, converted on your own machine, and saved back by the browser. There is no file-size limit and no account to create.
How do I convert an HDR file?#
- Drop your HDR file onto the converter at the top of this page, or click it to pick one from your computer.
- Choose the format you want out of it. FileFlip downloads the engine that conversion needs, once, and your browser caches it.
- Conversion starts the moment you pick the format, and the result is yours to download. The work happens in this tab, so nothing is uploaded and nothing is queued.
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 happens to a HDR file#
FileFlip converts HDR into 61 formats with ImageMagick, MuPDF and Pandoc, all of it inside the browser tab. Each conversion below names the engine it uses, what it downloads, and exactly what that conversion keeps or drops.
| Category | Image Files |
|---|---|
| File extension | .hdr |
| FileFlip support | Read and written |
| Conversions available | 61 |
| Engines | ImageMagick, MuPDF and Pandoc |
| Downloaded to your browser | 14.1 MB on the first conversion, then cached |
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.
The HDR file format reference covers the specification, the programs that open one, and what each conversion keeps or drops.
HDR 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.