CRN Format Hub - Online Crunch Converter & CRN Texture Viewer
Highly optimized free online CRN format tools. Enjoy our Crunch-based CRN Converter (Images to CRN) and CRN viewer resolving compression needs aimed at tight distributions sizes.
About CRN Format
CRN (Crunch) is a lossy texture container widely used to reduce package size while preserving practical quality for real-time graphics.
Small Distribution Size
Designed to minimize texture package footprint for web and game builds.
Fast Runtime Transcoding
Commonly transcoded to BC block-compressed formats during loading.
Browser Workflow
Works with WebAssembly pipelines for in-browser encode/decode tooling.
Pipeline Friendly
Integrates well with automated asset pipelines and batch conversion.
Technical Specifications
File Structure
- Compact CRN header stores dimensions, mip levels, and format metadata.
- Payload contains Crunch bitstream data for transcoding to BC formats.
- Supports mipmaps for efficient runtime texture sampling.
Compression Characteristics
Typical targets include BC1/BC3/BC5 style block-compressed outputs.
Compression quality can be tuned to balance size, speed, and fidelity.
Typical Use Cases
Web Asset Delivery
Reduce download size for browser-based 3D applications.
Legacy Crunch Pipelines
Maintain compatibility with existing Crunch-based production assets.
Runtime Transcoding
Transcode on load to GPU-native BC formats for rendering.
Asset Archive Distribution
Ship compact texture archives for multi-platform deployments.
Format Comparison
DDS usually stores final GPU-ready blocks; CRN stores a compact stream optimized for transport and later transcoding.
KTX2 is a modern Khronos container with broader ecosystem tooling; CRN remains lightweight for specific pipelines.
Basis focuses on universal transcoding workflows; CRN is closely tied to Crunch and BC-oriented pipelines.
PNG is lossless image storage, while CRN is lossy texture compression for runtime graphics workflows.
Related Tools
Encode to CRN
Convert source images into CRN compressed textures.
Decode CRN Files
Inspect CRN files by decoding and previewing RGBA output.
Upstream Toolchain
Crunch project provides the reference encoder/decoder implementation used by this toolchain.