Skip to content

HDR to DDS Converter

Convert HDR to DDS in your browser. HDR files usually come from HDRI environment maps, 360° panoramas and lighting simulation; DDS is the better fit for game textures and mods. You get an uncompressed 32-bit RGBA DDS texture with a single mip level, or DXT1 or DXT5 block compression if you choose it. Nothing is uploaded.

  • Processed locally
  • No upload, no wait
  • No sign-up
  • No watermark

Drop images here

or choose files · paste with Ctrl/⌘ V

HDR expected · other image formats also work

Files are processed on this device. Nothing is uploaded.0 B uploaded

How to use HDR to DDS

  1. 1

    Add your HDR files: drop them here, choose them, or paste from the clipboard.

  2. 2

    Choose the DDS compression: none for an exact 32-bit texture, DXT1 or DXT5 for smaller GPU-ready files.

  3. 3

    Click Convert. Each file is decoded and encoded in a background thread on this device.

  4. 4

    Download the .dds files one at a time or together as a ZIP.

Why use Aback Images for hdr to dds

Where the DDS goes next

DDS opens in game engines, Visual Studio, Paint.NET, GIMP, NVIDIA and Intel texture tools.

DDS next to HDR

The DDS is written uncompressed, so expect it to be several times larger than the HDR, which stores run-length encoded RGBE scanlines.

Written without a lossy pass

The DDS is written uncompressed, so the pixels decoded from the HDR arrive unchanged, apart from precision beyond 8 bits per channel.

Processed on your device

Your images are decoded, edited and encoded inside this browser tab by Web Workers. Nothing is uploaded to a server.

HDR vs DDS

What changes from HDR to DDS

Encoding: the HDR uses run-length encoded RGBE scanlines; DDS uses block compression (BC1 to BC7, also called DXT) or uncompressed RGBA, and the download is an uncompressed 32-bit RGBA DDS texture with a single mip level, or DXT1 or DXT5 block compression if you choose it.

Bit depth: an 8-bit mantissa per channel sharing an 8-bit exponent (RGBE), 32 bits per pixel in the HDR; DDS allows 8 bits per channel for common texture formats, and the DDS written here has 8 bits per channel. The high dynamic range is mapped to 8 bits per channel, and values above white clip.

Colour: linear RGB (or XYZ in the XYZE variant) in the HDR; DDS supports RGB(A); normal maps and packed masks store data rather than colour, written here as 8-bit sRGB.

Metadata: the HDR can carry a text header with FORMAT, EXPOSURE and optional comments; DDS can carry a 128-byte header (plus a DX10 header) describing the pixel format, nothing about the picture, but nothing is copied across.

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.

HDR files usually come from HDRI environment maps, 360° panoramas and lighting simulation.

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.

When converting HDR to DDS makes sense

DDS is the better choice for game textures and mods, while HDR suits 3D lighting and environment maps.

DDS strengths: Loads straight into GPU memory; Mipmaps included. Drawbacks to weigh: Not viewable outside game tools; Lossy block compression.

Limitations

  • Light values above 1.0 are clipped rather than tone-mapped, so the sun and bright sky turn flat white.
  • Environment maps are 2:1 equirectangular panoramas, so the picture looks stretched near the top and bottom, as it should.
  • Files in the XYZE variant cannot be read here; RGBE files, the common kind, can.
  • The DDS has a single mip level, so generate mipmaps in your engine or texture tool if it needs them.
  • Uncompressed DDS textures take 4 bytes per pixel; DXT1 is an eighth of that and DXT5 a quarter, at the cost of lossy 4×4 block compression.

Frequently asked questions

Does converting HDR to DDS lose quality?

DDS is written uncompressed, so the pixels are stored exactly as decoded. The high dynamic range is mapped to 8 bits per channel, and values above white clip.

Which apps open DDS files?

Game engines, Visual Studio, Paint.NET, GIMP, NVIDIA and Intel texture tools. 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.