GRAY to HDR Converter
Processing entirely on your device — large files may take a moment.
Converting HDR to PNG produces a tone-mapped preview usable in any image viewer. If your files are still in GRAY format, this page is the shortcut: GRAY is the single-channel spelling of raw grayscale dumps — the same unformatted luminance bytes the GRAYA variant adds alpha to.
iLoveConverter processes everything locally on your computer, which makes it private and fast: no upload wait, no server storage, no limits. Add as many files as you like — batch conversion is built in.
How to convert GRAY to HDR
- 1
Select your files
Drag & drop your GRAY files onto the area above, or click to browse. You can add multiple files at once for batch conversion.
- 2
Convert instantly
Click "Convert to HDR". The conversion runs entirely inside your browser using WebAssembly — no upload, no queue, no waiting.
- 3
Download results
Download each converted HDR file individually, or grab everything at once as a ZIP archive.
About the GRAY format
The Grayscale + Alpha (raw) coder of the ImageMagick set — the raw-pixels format is written natively by the magick.wasm engine, entirely in your browser.
Obscure coder formats like this are exactly what template-driven converters list and never actually convert — here it really works.
+Strengths
- ✓Written natively by ImageMagick
- ✓Runs entirely in your browser
- ✓Free, private, no watermarks
!Limitations
- −Niche format — few modern readers
- −Feature subset varies by coder
- −Keep the original for re-editing
About the HDR format
HDR (Radiance RGBE) is the veteran high-dynamic-range format of lighting research and 3D rendering: pixels stored as a shared 8-bit exponent plus per-channel mantissas, letting one file hold both a sun and a shadow with no clipping. HDRI environment maps for 3D scenes are almost always HDR files.
Standard image viewers show it badly or not at all, because the values can exceed what a screen can display. Converting HDR to PNG tone-maps the file into an 8-bit preview — good for quick inspection, though the floating-point original remains the render-grade master.
+Strengths
- ✓True high-dynamic-range values
- ✓The standard of HDRI environment maps
- ✓Compact for its precision
!Limitations
- −Not display-ready — needs tone mapping
- −Viewer support is scarce
Why convert GRAY to HDR?
Converting makes sense where the strengths of HDR meet what GRAY cannot give you. True high-dynamic-range values Meanwhile Niche format — few modern readers One pass through the converter above puts your file on the right side of that trade-off.
Frequently asked questions
Is this GRAY to HDR converter really free?
Yes — completely free, with no sign-up, no watermark and no daily conversion limits. The site is supported by advertising.
Are my files uploaded to a server?
No. The conversion runs entirely inside your browser using WebAssembly, so your files never leave your device — that is what makes it instant and private.
Does it work on Windows, Mac, iPhone and Android?
Yes. Anything with a modern browser works: Windows, macOS, Linux, Android and iOS. No software installation is required.
Will I lose quality converting GRAY to HDR?
No — HDR is a lossless format, so every pixel of the converted image matches your original GRAY file. You can also adjust the quality/size balance before converting when the target format supports compression.
Can I convert several GRAY files at once?
Yes — drop as many files as you like into the tool and they are converted in one batch. When more than one file comes out, everything is bundled into a ZIP for a single download.
Will transparent areas survive the conversion to HDR?
Transparency is kept whenever HDR actually supports an alpha channel. If the target format has none (like JPG), transparent areas are flattened onto a white background — that is a property of the format, not of this tool.