Online ASTC Viewer & Decoder - Open, View and Convert ASTC to PNG
Unpack ASTC variables into native views. Use our ASTC Viewer to fetch insights and easily convert ASTC formats successfully right away to PNG.
Related Resources
Upload ASTC File
Key Features
100% Browser-Based
All decoding happens locally. No uploads, complete privacy.
All Block Sizes Supported
Decode ASTC files with any block size from 4×4 to 12×12.
Instant Preview
Real-time texture preview with canvas rendering.
Channel Viewer
View RGBA, RGB, or individual R/G/B/A channels separately.
Export to PNG
Download decoded textures as standard PNG images.
Free & Fast
No limits, no registration, WebAssembly-powered speed.
How to Use ASTC Decoder
Upload Your ASTC File
Drag and drop your .astc file into the upload area, or click to browse and select a file from your computer.
View File Information
Once uploaded, the decoder will automatically parse the ASTC file and display detailed information including dimensions, block size, and file size.
Preview and Inspect
Use the preview panel to visualize your texture. You can zoom in/out, reset the view, and switch between different color channels.
Export if Needed
Download the decoded texture as a PNG file for use in other applications or further processing.
Frequently Asked Questions
Yes. This tool works as an ASTC viewer for .astc files and also lets you decode ASTC textures and export them as PNG.
ASTC supports 14 different block sizes: 4×4, 5×4, 5×5, 6×5, 6×6, 8×5, 8×6, 8×8, 10×5, 10×6, 10×8, 10×10, 12×10, and 12×12.
Yes, absolutely. All ASTC file processing happens entirely in your browser using WebAssembly. Your files are never uploaded to any server.
The decoder can handle ASTC files up to 100MB in size. Most game textures are well below this limit.
Yes, the decoder supports both LDR and HDR ASTC files, though HDR content will be tone-mapped for display.
The ASTC decoder works in all modern browsers that support WebAssembly and WebGL, including Chrome, Firefox, Safari, and Edge (version 79+).
Once the page is loaded, the core decoding functionality works offline. However, initial page load requires an internet connection.
To create ASTC files, use our encoder tool or other texture compression tools like ARM's astcenc or Compressonator that support ASTC encoding.