ComfyUI Node Tips

This note covers specific configurations, tricks, and advanced formatting conventions for various built-in ComfyUI nodes.

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💾 Save Image Filename Conventions

The native Save Image node in ComfyUI allows you to customize the output paths and filenames using placeholders in the filename_prefix widget. You can dynamically insert date, time, and values from other nodes.

1. Date & Time Placeholders

You can format the date and time using %date:FORMAT% placeholders. The formatting matches standard time specifiers:

Specifier	Description	Example Output
yyyy	4-digit Year	2026
MM	2-digit Month (01-12)	06
dd	2-digit Day (01-31)	30
hh	2-digit Hour (00-23)	14
mm	2-digit Minute (00-59)	35
ss	2-digit Second (00-59)	09

Examples:

• %date:yyyyMMdd_hhmmss% $\rightarrow$ 20260630_143509_00001.png
• myproject_%date:yyyy-MM-dd% $\rightarrow$ myproject_2026-06-30_00001.png

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2. Subfolders Creation

You can organize your outputs into subfolders dynamically by inserting a forward slash (/) in the prefix path:

• Daily Folders: %date:yyyy-MM-dd%/image
  • Result: Images will be saved inside an output directory structured as /output/2026-06-30/image_00001.png.
• Project Subfolders: projects/my_model/%date:MM-dd%_render
  • Result: /output/projects/my_model/06-30_render_00001.png.

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3. Dynamic Node Values

You can dynamically embed parameters (widget values) from other nodes in your workspace using the %Node Name.widget_name% syntax.

WARNING

The Node Name must match the title of the node in your workflow exactly. If you renamed a node (e.g. renamed "KSampler" to "MySampler"), you must use the renamed title.

Examples:

• Dimensions: %Empty Latent Image.width%x%Empty Latent Image.height%_render
  • Result: 512x512_render_00001.png
• Inference Parameters: img_%KSampler.seed%_steps%KSampler.steps%
  • Result: img_8923482348_steps20_00001.png

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💡 General Tips

• Avoid Input Conversion: Keep filename_prefix as a widget string when utilizing these formatting placeholders. Converting filename_prefix to a node input (via right-click) can occasionally bypass the placeholder parser and output literal strings.
• Save Image Extended: If you need more advanced control over counter resets, prompt embedding, or automatic metadata saving, install the custom node Save Image Extended via the ComfyUI Manager.