BMP to DDS Converter

What happens when you convert BMP to DDS

• ImageMagick, the open-source image toolkit, reads the BMP on our conversion server and saves it as a DDS texture, block compressed as DXT5 when the image has transparency and as DXT1 when it does not.
• Transparent areas stay transparent.
• DDS compression works on blocks of 4 by 4 pixels and is lossy, as in every game texture: sharp edges and smooth gradients pick up slight blockiness up close.
• Mipmaps, the smaller copies a game uses for distant surfaces, are added when both sides are powers of two, such as 512 by 512 or 1024 by 2048. A texture of any other size gets none, and most game engines expect power-of-two sizes anyway.
• This conversion runs on our server: the file is uploaded, converted, and deleted together with the result as soon as the result has been sent back to you. Nothing is kept. Files up to 25 MB are accepted.

How to convert BMP to DDS online

1. Press "Choose BMP files" and select one or more files, or drag them onto the box. Files up to 25 MB each can be converted.
2. There are no settings to choose: the converter keeps everything the target format can hold.
3. Press "Convert to DDS". The file is uploaded to our conversion server, converted in a few seconds, and deleted together with the result as soon as the result is sent back.
4. Save each DDS with its download button. Our server has already deleted both your BMP and the DDS by then.

Why convert BMP to DDS?

BMP files usually come from Windows software, embedded displays and legacy tools. People convert them to DDS because DDS is the texture format games and 3D engines load straight onto the graphics card, and the one game mods have to use.

In short, BMP is good at what it was made for, and DDS is the more practical choice when the file has to open, upload or print somewhere else. BMP opens in browsers and every Windows image tool, while DDS does not open in browsers; Paint.NET, GIMP and game modding tools open it, and Photoshop with NVIDIA's plug-in.

How to convert BMP to DDS on Windows, Mac, iPhone and Android

On Windows

Open this page in Chrome, Edge or Firefox, drag your BMP files in from File Explorer, and press Convert. Each DDS is saved to your Downloads folder.

On a Mac

Safari, Chrome and Firefox all work. Drag the BMP files from Finder onto the drop zone and the DDS files land in Downloads.

On iPhone and iPad

Open the page in Safari and tap Choose BMP files. You can pick from Photos or from the Files app. The converted DDS appears in Files, in the Downloads folder.

On Android

Open the page in Chrome, tap Choose BMP files and pick them from Files or your gallery. The DDS is saved to the Download folder, where any file manager can find it.

Best settings for BMP to DDS

There are no settings: the texture keeps the image's size, compressed as DXT5 when it has transparency and DXT1 when it does not.

If the game or engine needs a power-of-two size, such as 1024 by 1024, resize the image before converting, so the texture also gets mipmaps.

BMP vs DDS: the differences

About BMP and DDS files

What is a BMP file?

BMP usually stores pixels with no compression at all, so a 12 megapixel photo is about 36 MB. That size is the price of being readable by almost any program ever written for Windows.

What is a DDS file?

DDS stores a texture the way a graphics card uses it: compressed in blocks of 4 by 4 pixels that the GPU decodes on the fly, often with mipmaps, smaller copies for distant surfaces. That is why game mods are full of DDS files, and why ordinary image viewers cannot open them.

BMP to DDS not working? Common problems

• "Files up to 25 MB can be converted." Server conversions have a size limit. Save the image at a smaller size first.
• "The conversion took too long and was stopped." Very long or complex files can pass the 90 second limit. Split the file and convert the parts.
• "This file is not really in BMP format." The converter checks every file before it runs anything, so a file of another format renamed to .bmp is refused. Choose the page for its real format.

Convert BMP to DDS from the command line

ImageMagick does the same on your own computer:

magick input.bmp output.dds

Converting on your own computer keeps the file entirely local, which is worth it for very large or very sensitive documents. For everything else, the converter on this page does it without installing anything.