ComfyUI_jxl_support

ComfyUI JXL Support

Load and save JPEG XL (.jxl) images in ComfyUI with lossy/lossless compression and optional workflow metadata compression.

Installation

open ComfyUI/custom_nodes/
git clone https://github.com/koloved/ComfyUI_jxl_support

Restart ComfyUI after installation.

Nodes

Save Image (JXL)

| Input | Type | Default | Description | |---|---|---|---| | images | IMAGE | — | Batch of images to save | | filename_prefix | STRING | ComfyUI | Output filename prefix | | quality | INT (0–100) | 100 | 100 = lossless; lower = smaller file | | compress_metadata | BOOLEAN | True | Brotli-compress embedded workflow metadata |

Load workflow from JXL Image

Reads embedded workflow metadata for drag-and-drop recovery.

Feature highlights

• Lossless at quality=100 — pixel-perfect output, ~40% smaller than PNG.
• Lossy at quality < 100
• Metadata compression toggle — disable compress_metadata to compare file size with uncompressed vs Brotli-compressed workflow metadata.
• Drag-and-drop restore — JS extension embeds workflow data for one-click recovery.

Size comparison (real-world example)

Format comparison (1024×1024 render)

| Format | Size | |---|---| | PNG (lossless) | 1.58 MB | | JXL lossless (quality=100) | 0.99 MB |

Metadata compression impact (quality=40)

| compress_metadata | File size | |---|---| | True (Brotli) | 99 KB | | False (raw JSON) | 206 KB |

Metadata compression is most noticeable on lossy files — workflow JSON can be 100+ of KB uncompressed.

Dependencies

Installed via requirements.txt: | Package | Purpose | |---|---| | imagecodecs | JXL encode / decode | | brotli | Workflow metadata compression |