ARW to HDR Converter
Convert ARW to HDR in your browser. The full-size JPEG Sony stores in the file is what gets converted, so the sensor coding never reaches the output. No raw development happens here. You get a Radiance RGBE (.hdr) file, with the 8-bit sRGB values converted to linear light. Nothing is uploaded.
- Processed locally
- No upload, no wait
- No sign-up
- No watermark
Drop images here
or choose files · paste with Ctrl/⌘ V
RAW expected · other image formats also work
How to use ARW to HDR
- 1
Add your ARW files: drop them here, choose them, or paste from the clipboard.
- 2
There is nothing to tune: the HDR is written losslessly. Resizing and rotating are under More options if you need them.
- 3
Click Convert. Each file is decoded and encoded in a background thread on this device.
- 4
Download the .hdr files one at a time or together as a ZIP.
Why use Aback Images for arw to hdr
Where the HDR goes next
HDR opens in Blender, Photoshop, Houdini, Unreal Engine, Unity and Affinity Photo.
HDR next to ARW
The HDR holds the camera preview's pixels with lossless compression: usually smaller than a 25 to 80 MB raw file, though far larger than a JPEG of the same photo.
No new artefacts
The preview inside the ARW is a camera JPEG; the HDR stores its decoded pixels losslessly, so this step adds no compression damage of its own.
Processed on your device
Your images are decoded, edited and encoded inside this browser tab by Web Workers. Nothing is uploaded to a server.
ARW vs HDR
What changes from ARW to HDR
Encoding: the ARW uses Sony's lossy compressed raw, uncompressed (since the A7R II) or lossless compressed (since the A1); HDR uses run-length encoded RGBE scanlines, and the download is a Radiance RGBE (.hdr) file, with the 8-bit sRGB values converted to linear light.
Bit depth: 12 or 14 bits per channel in the ARW; HDR allows an 8-bit mantissa per channel sharing an 8-bit exponent (RGBE), 32 bits per pixel, and the HDR written here has RGBE, 32 bits per pixel. The sensor's 12 or 14 bits are not used: the 8-bit camera preview is converted.
Colour: camera RGB from a Bayer mosaic in the ARW; HDR supports linear RGB (or XYZ in the XYZE variant), written here as linear-light RGB.
Metadata: the ARW can carry EXIF, Sony maker notes, a thumbnail and a full-size JPEG; HDR can carry a text header with FORMAT, EXPOSURE and optional comments, but nothing is copied across.
About ARW
ARW is the raw format of Sony Alpha, RX and Cyber-shot cameras. It stores the sensor data (compressed, uncompressed or lossless compressed, depending on the model) with a full-size JPEG preview.
ARW is TIFF-based: the first directory carries EXIF and Sony's JPEG preview and the sensor data sits in a sub-directory. In Sony's classic compressed raw each block of 16 same-colour pixels keeps an 11-bit maximum and minimum plus 7-bit steps for the rest, which can leave artefacts beside high-contrast edges.
ARW files usually come from Sony Alpha mirrorless and SLT cameras, RX compacts and some Cyber-shot models.
About HDR
Radiance .hdr stores high dynamic range light values, widely used for 3D environment maps and HDRI lighting.
A Radiance file starts with '#?RADIANCE' (or '#?RGBE'), text lines such as FORMAT=32-bit_rle_rgbe and EXPOSURE, a blank line, a resolution line like '-Y 2048 +X 4096', then the scanlines.
When converting ARW to HDR makes sense
HDR is the better choice for 3D lighting and environment maps, while ARW suits editing Sony photos in a raw developer.
HDR strengths: True high dynamic range; Standard for HDRI environment maps. Drawbacks to weigh: Needs tone mapping to view on normal screens.
Limitations
- Creative Look or Picture Profile settings are baked into that preview; a raw editor can start again from neutral.
- No range is added: the HDR holds the 8-bit picture in linear light, and nothing in it is brighter than the original white.
- 3D software treats the file as linear light, so an ordinary photo used as an environment map may need its exposure raised to light a scene well.
More conversions
Related tools
Convert HDR to ARW in your browser, saved as a Linear DNG, the raw file every ARW editor also opens. Batch, private, no uploads.
Convert ARW to JPG in your browser, made from the full-size preview your Sony camera stored in the file. Batch, private, no uploads.
Shrink JPG, PNG, WebP, AVIF and GIF files with MozJPEG, OxiPNG and modern codecs, with a live before/after preview.
Resize to exact pixels, a percentage or a longest side, with Lanczos3 and Magic Kernel resampling. Batch ready.
Strip EXIF, GPS, XMP, IPTC and comments losslessly. Pixels are never re-encoded for JPG, PNG and WebP.
Convert between 34 image formats in bulk: HEIC, WebP, AVIF, JPEG XL, PNG, JPG, GIF, TIFF, SVG, ICO, PSD, RAW and more.
Frequently asked questions
Does converting ARW to HDR lose quality?
HDR is written losslessly, so the pixels are stored exactly as decoded. Those pixels come from the camera's JPEG preview, so its compression stays, but nothing new is lost. The sensor's 12 or 14 bits are not used: the 8-bit camera preview is converted.
Does saving as HDR make a real HDRI?
No. A real HDRI is merged from several exposures. This file holds an 8-bit image in linear light, so 3D software reads it correctly, but it has no more range than the source.
Which apps open HDR files?
Blender, Photoshop, Houdini, Unreal Engine, Unity and Affinity Photo. It does not open in web browsers.
Are my images uploaded anywhere?
No. Processing happens inside your browser with WebAssembly and Web Workers. The site only downloads the app code and codecs; your files never leave your device. You can confirm this with the live upload counter on the tool, or in your browser's network panel.
Can I process many files at once?
Yes. Drop a whole selection or folder. Files are processed in parallel on several worker threads, each result can be downloaded on its own, and everything can be saved as one ZIP.
Is it free? Is there a file limit or watermark?
It is free with no account, no watermark and no daily limit. The only limit is your device's memory: very large images (over roughly 100 megapixels) may be refused to keep the tab from crashing.