DDS to HDR Converter
Convert DDS to HDR in your browser. DDS files usually come from DirectX games, game mods and texture tools such as NVIDIA Texture Tools and Intel's texture plugin; HDR is the better fit for 3D lighting and environment maps. 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
DDS expected · other image formats also work
How to use DDS to HDR
- 1
Add your DDS files: drop them here, choose them, or paste from the clipboard.
- 2
Pick the colour that replaces transparent areas, since HDR has none.
- 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 dds to hdr
Where the HDR goes next
HDR opens in Blender, Photoshop, Houdini, Unreal Engine, Unity and Affinity Photo.
HDR next to DDS
Both sides are lossless, so the size depends on how well the HDR encoder handles this picture compared with the DDS's block compression (BC1 to BC7, also called DXT) or uncompressed RGBA.
Written without a lossy pass
The HDR is written losslessly, so the pixels decoded from the DDS arrive unchanged.
Processed on your device
Your images are decoded, edited and encoded inside this browser tab by Web Workers. Nothing is uploaded to a server.
DDS vs HDR
What changes from DDS to HDR
Encoding: the DDS uses block compression (BC1 to BC7, also called DXT) or uncompressed RGBA; 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: 8 bits per channel for common texture formats in the DDS; 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.
Colour: RGB(A); normal maps and packed masks store data rather than colour in the DDS; HDR supports linear RGB (or XYZ in the XYZE variant), written here as linear-light RGB.
Transparency: the DDS stores it as alpha inside the compressed blocks (BC2, BC3, BC7) or a 1-bit cut-out (BC1); the HDR has none, so transparent areas are filled with the colour you choose.
Other images: the DDS can hold mipmaps, cubemap faces or texture arrays; only the main image is converted.
Metadata: the DDS can carry a 128-byte header (plus a DX10 header) describing the pixel format, nothing about the picture; HDR can carry a text header with FORMAT, EXPOSURE and optional comments, but nothing is copied across.
About DDS
DDS is a GPU texture format used by DirectX games. It stores block-compressed textures (DXT/BC) and mipmaps that graphics cards decode directly.
A DDS file starts with 'DDS ' and a 124-byte header giving the size, mipmap count and pixel format: a FourCC such as DXT1 or DXT5, or 'DX10' followed by an extra header naming a DXGI format. The largest mipmap comes first.
DDS files usually come from DirectX games, game mods and texture tools such as NVIDIA Texture Tools and Intel's texture plugin.
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 DDS to HDR makes sense
HDR is the better choice for 3D lighting and environment maps, while DDS suits game textures and mods.
HDR strengths: True high dynamic range; Standard for HDRI environment maps. Drawbacks to weigh: Needs tone mapping to view on normal screens.
Limitations
- Only the top-level image (the largest mipmap of the first surface) is converted; smaller mipmaps and other cubemap faces are left out.
- Normal maps and packed masks hold data rather than colours, so they look purple or odd as ordinary pictures.
- 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.
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Frequently asked questions
Does converting DDS to HDR lose quality?
HDR is written losslessly, so the pixels are stored exactly as decoded. Not carried over: any mipmaps.
What happens to transparency when converting DDS to HDR?
DDS stores transparency as alpha inside the compressed blocks (BC2, BC3, BC7) or a 1-bit cut-out (BC1). HDR has no alpha channel, so transparent pixels are composited onto a solid colour, white unless you pick another. To keep transparency, convert to PNG, WebP or AVIF instead.
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.