jpeg-is-fine

JPEG is Fine

A focused, minimal JPEG-saving node for ComfyUI optimized for high-quality output with proper chroma handling.

Features

• 4:4:4 chroma subsampling — no color quality loss from chroma downsampling
• Counter-based file naming — automatic collision avoidance, no overwrites
• Workflow preservation — embedded in EXIF metadata and optional JSON export
• Baseline JPEG — maximum compatibility, with optimized encoding for smaller files at no quality cost

Installation

ComfyUI Manager (recommended): open the Custom Nodes Manager, search for JPEG is Fine and click Install. Restart ComfyUI when prompted.

Manual: clone the repository into your custom_nodes folder:

cd ComfyUI/custom_nodes
git clone https://github.com/a5ah1/jpeg-is-fine

Restart ComfyUI and refresh your browser. The folder name doesn't matter, and no extra Python packages are needed.

Usage

Find the node under image category as "JPEG is Fine".

Inputs

| Input | Default | Description | |-------|---------|-------------| | images | — | Input images from upstream node | | filename_prefix | image | Base name for output files | | directory | "" | Subdirectory under ComfyUI output folder (use / for nesting) | | delimiter | - | Character(s) between prefix and counter | | counter_digits | 4 | Zero-padding width (4 = 0001) | | quality | 92 | JPEG quality (1-100) | | save_workflow_json | Subdirectory | JSON export mode |

Output

| Output | Description | |--------|-------------| | images | The input images, unchanged. Optional: leave it unconnected, or use it to chain further nodes after saving |

File Naming

Files are named {prefix}{delimiter}{counter}.jpeg:

• render-0001.jpeg
• photo_001.jpeg
• out-000001.jpeg

The counter automatically increments based on existing files in the directory.

Characters that aren't allowed in filenames (/ \ : * ? " < > |) are replaced with _ in the prefix and delimiter, so SDXL\model or 12:30 become SDXL_model and 12_30. The node logs a warning in the console when this happens. To save into subfolders, use directory.

directory is always inside the ComfyUI output folder. Absolute paths, drive letters and .. are rejected with an error.

Workflow JSON Export

• Disabled — No JSON export
• Sidecar — JSON saved alongside the image (render-0001.json)
• Subdirectory — JSON saved to {prefix}_workflows/ subfolder

Workflow data is always embedded in the JPEG's EXIF metadata (tag 270: ImageDescription), regardless of JSON export setting. EXIF has a ~64KB limit, so if the workflow is too large, only the prompt is embedded (a warning is logged). Enable JSON export if you work with very large workflows.

Why "JPEG is Fine"?

JPEG gets a bad reputation, but with proper settings it's excellent for AI-generated images:

• 4:4:4 subsampling preserves color detail that 4:2:0 (the default) destroys
• Quality 92 is visually lossless for most content
• Baseline JPEG works everywhere
• File sizes are typically 5-10x smaller than PNG with no visible quality loss

What This Node Doesn't Do

• No format switching (JPEG only)
• No preview (chain a Preview Image node)
• No filename templating (just prefix + counter)
• No progressive JPEG option
• No chroma subsampling options (always 4:4:4)

License

MIT — see LICENSE.