Boyo Saver

If you've ever upscaled or refined an image and wanted to keep both versions to compare later, you know the pain of juggling two save nodes with two different filenames and hoping you can tell which pair they belong to. BoyoSaver is the two-for-one answer: one node, original_image and upscaled_image in, and it writes both to disk as a numbered pair sharing a prefix - boyo001A.png and boyo001B.png, next one up, every run.

It's an output node with no returns. The inputs are original_image, upscaled_image, prefix (default boyo), and directory (default output - note: a plain relative path, not the ComfyUI output folder). Files land as {prefix}{counter:03d}A.png (original) and {prefix}{counter:03d}B.png (upscaled).

How it works

There's an in-memory counter that increments each run - boyo001, boyo002, boyo003... so a session of comparisons auto-numbers itself. The counter starts at zero when ComfyUI restarts, so if you restart mid-batch you can overwrite earlier pairs. It saves only the first frame of each input tensor, and writes PNGs via Pillow. That's the whole mechanism - deliberately no surprises.

Where it fits

The natural home is a hires-fix or upscale chain: your base image on original_image, the output of an upscaler or detailer on upscaled_image, and you walk away with an automatically-organised before/after archive. It's also handy for quick quality comparisons - run the same source through two different upscalers and you get boyo001A.png (shared original) plus boyo001B.png from chain one and boyo002B.png from chain two, both keyed to the same A.

If your goal is a ControlNet-style training dataset instead, the pack's BoyoPairedImageSaver is the better tool - it writes _original.png / _controlnet.png pairs into the ComfyUI output folder with collision-safe numbering. BoyoSaver is the casual comparison-tool version.

Installing it

Ships with Boyonodes (DragonDiffusionbyBoyo):

cd ComfyUI/custom_nodes
git clone https://github.com/DragonDiffusionbyBoyo/Boyonodes

Restart ComfyUI or install "Boyonodes" via ComfyUI Manager. No extra dependencies - Pillow and numpy, both already present.

Gotchas

• The default directory (output) is relative to the ComfyUI working directory, which trips people up; if you want files in the ComfyUI output/ folder, type that explicitly.
• The counter is per-process, not persistent. Restart ComfyUI and numbering restarts - existing files with the same prefix can be overwritten. Change the prefix between sessions if that matters.
• Only image[0] is saved per input. Feed single images.

Small, single-purpose, and pleasant to have around for anyone who likes keeping the receipts on their upscales.