ICO to DDS Converter
Convert ICO to DDS in your browser. ICO files usually come from website favicons, Windows programs and installers; 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
ICO expected · other image formats also work
How to use ICO to DDS
- 1
Add your ICO files: drop them here, choose them, or paste from the clipboard.
- 2
Choose the DDS compression: none for an exact 32-bit texture, DXT1 or DXT5 for smaller GPU-ready files.
- 3
Click Convert. Each file is decoded and encoded in a background thread on this device.
- 4
Download the .dds files one at a time or together as a ZIP.
Why use Aback Images for ico 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 ICO
The DDS is written uncompressed, so expect it to be several times larger than the ICO, which stores each size stored as a headerless BMP or as a complete PNG.
Written without a lossy pass
The DDS is written uncompressed, so the pixels decoded from the ICO 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.
ICO vs DDS
What changes from ICO to DDS
Encoding: the ICO uses each size stored as a headerless BMP or as a complete PNG; 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: 1 to 32 bits per pixel, set per size in the ICO; DDS allows 8 bits per channel for common texture formats, and the DDS written here has 8 bits per channel.
Colour: RGB or a palette, per image in the ICO; DDS supports RGB(A); normal maps and packed masks store data rather than colour, written here as 8-bit sRGB.
Transparency: the ICO stores it as 8-bit alpha in 32-bit and PNG entries, or a 1-bit mask in old icons; the DDS keeps it as alpha inside the compressed blocks (BC2, BC3, BC7) or a 1-bit cut-out (BC1).
Other images: the ICO can hold several sizes of the same picture, typically 16, 32, 48 and 256 px; only the main image is converted.
Metadata: the ICO can carry only a directory of the sizes inside, with no EXIF; 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 ICO
ICO is a container that bundles several sizes of the same icon (16, 32, 48, 256 px) into one file. It is still the most compatible format for website favicons and Windows app icons.
An ICO starts with a 6-byte ICONDIR (type 1 for icons) and a 16-byte entry per image giving width, height, colour count and offset. Each image is either a BMP without its file header plus an AND mask, or a complete PNG.
ICO files usually come from website favicons, Windows programs and installers.
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 ICO to DDS makes sense
DDS is the better choice for game textures and mods, while ICO suits favicons and Windows icons.
DDS strengths: Loads straight into GPU memory; Mipmaps included. Drawbacks to weigh: Not viewable outside game tools; Lossy block compression.
Limitations
- The largest image in the icon is the one converted; smaller sizes that were hand-tuned for 16 px are not carried over.
- 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.
More conversions
Related tools
Convert DDS to ICO in your browser, multi-size icons for favicons and Windows. Batch, private, no uploads.
Convert ICO to PNG in your browser, ready for screenshots, logos, graphics and anything that needs transparency. 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 ICO to DDS lose quality?
DDS is written uncompressed, so the pixels are stored exactly as decoded. Not carried over: any several sizes of the same picture.
Is transparency kept in the DDS?
Yes. ICO stores it as 8-bit alpha in 32-bit and PNG entries, or a 1-bit mask in old icons, and the DDS is written with an alpha channel, so transparent areas stay transparent.
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.