All about DDS files

Microsoft's texture format for games and 3D applications

Last updated on April 25, 2026 by Sören Ramspeck with the experience of more than 128,393,575 converted files since 2013.

DDS stands for DirectDraw Surface and is a file format developed by Microsoft for storing textures and surface data for 3D applications. The format was introduced alongside DirectX 7 to store both compressed and ^[1]uncompressed textures. The header is directly derived from the DirectDraw 7 structures, and although DirectDraw itself has long been considered a legacy API, the file format lives on and is still frequently used^[2]. Anyone who has ever unpacked game files or even created mods for games has almost certainly come across .dds files—and may not have been able to view them directly.

Technical Background

Back then, graphics cards often had only 8 MB of video memory, and uncompressed textures would eat through it in a matter of seconds. The solution came from S3 Graphics, which developed S3 Texture Compression (S3TC), a method that could shrink texture data to one-quarter to one-sixth of its original size without requiring the graphics card to first laboriously decompress the data before rendering. In March 1998, Microsoft licensed this technology for DirectX^[3]. S3TC was originally developed for the Savage 3D graphics card and had been ^[4]patented in 1997. Microsoft chose this specific algorithm because it delivered the best image quality and could be implemented ^[3]cost-effectively in hardware. With DirectX 7, the compressed texture file then got its own container: the DDS format.

Further Development of the Format

What began in 1999 as a simple texture container has been significantly expanded over the years. DirectX 8.0 added support for volume textures, and starting with Direct3D 10, texture arrays are also supported^[1]. An extended header (DX10 extension) was introduced to resolve a rather unsightly issue: The format names from Direct3D 9 and Direct3D 10 conflicted with each other, which would have led to ambiguities during ^[2]loading without the new header. With DirectX 11, additional compression methods were added, enabling, among other things, HDR textures (for realistic lighting conditions) and overall higher color fidelity.

DDS: Image or Container Format?

DDS is less of a traditional image format and more of a container format. In addition to simple 2D textures, a single DDS file can also contain cube maps (six sides of an environmental reflection, as needed for skies or reflective surfaces), volume textures (for effects like fog or smoke), and complete mipmap chains. The latter are texture variants with decreasing resolution, so that an object in the distance does not have to load the same high-resolution texture as one directly in front of the camera. The five original compression formats, DXT1 through DXT5, were^[4] renamed BC1 through BC3 with Direct3D 10, although DXT2 and DXT4 were rarely used in practice.

Applications of DDS files

The format is supported by virtually every major game engine, including Unreal Engine, Unity, and CryEngine. Typical applications include diffuse maps (the actual coloring of a surface), normal maps (simulated surface details such as grooves or bumps), specular maps (control of gloss and reflections), and all other texture types found in a modern 3D game.
Although DDS was originally developed for DirectX, it can also be used in OpenGL via the OpenGL ^[4]extension GL_EXT_texture_compression_s3tc. So anyone who thinks DDS is exclusively a Windows thing is mistaken. The format is also used outside the gaming industry, for example in architectural visualizations or simulations.

Software Support

Various programs are available for opening and editing DDS files, including Adobe Photoshop (with a plugin), GIMP (with a DDS plugin), Paint.NET, and IrfanView. Microsoft maintains its own open-source libraries on GitHub—DirectXTex and DirectXTK—which fully support the format. Alternatively, DDS files can be converted directly in the browser to common formats like PNG or JPG using file-converter-online.com.

Sources

[1] Microsoft Learn: DDS – Win32 apps
[2] Chuck Walbourn / Microsoft DirectX SDK Blog: The DDS File Format Lives
[3] Microsoft Licenses 3-D Graphics Technology From S3 Incorporated
[4] Wikipedia S3 Texture Compression