Quick Size (SD15)

The one that keeps you honest about SD 1.5's resolution

Stable Diffusion 1.5 is old now, but it's not dead - its LoRA archive and low-VRAM install base keep it running on modest cards, and the #1 way people wreck their SD1.5 results is generating way above its native 512×512 and getting tiled, stretched anatomy. Quick Size (SD15) is the SD1.5 member of the ComfyUI-QuickSize pack: a dropdown that outputs width and height integers tuned to what SD1.5 actually wants, so "generate at native, then upscale" stops being advice you ignore.

It works like the pack's other nodes - pick from hardcoded resolution tables, get two INTs - but with one difference in the UI: instead of a megapixels tier, it has a 1.5x toggle. Off, you get the classic 512-based table (512×512, 768×512 for 3:2, 912×512 for 16:9). On, you jump to the ~768 tier (768×768, 1152×768, 1360×768). The author's own framing in the pack's announcement: the 1x option is the recommended size, and 1.5x is "live dangerously" territory.

The inputs that matter:

• preset - 1:1, 3:2, 2:3, 4:3, 16:9, or 9:16.
• orientation - horizontal or vertical.
• 1.5x - the resolution booster, default off.

Outputs are width and height INTs, wired into Empty Latent Image.

Now the trap, and this one is real - I checked the source. The 9:16 option is listed in the preset dropdown, but it's not present in either resolution table. Pick 9:16 and the code silently falls back to 1:1, so you get a 512×512 square (or 768×768 at 1.5x), not a portrait. It's not a crash, it's a quiet wrong answer - the worst kind. If you want portrait SD1.5, use 2:3 (512×768) and orientation vertical instead.

One honest note about the 1.5x tier: the community's rule of thumb is SD1.5 degrades above ~768 - the KB's own guidance says "up to 768×768 with quality loss" - so the 1.5x toggle is really a quality/VRAM compromise, not a free lunch. The clean path is generating at 512-native and letting a hires pass or an upscaler do the heavy lifting, which is exactly what the toggle tempts you to skip.

Installing it

Identical to the rest of the pack, and it's featherweight - no models, no extra dependencies:

cd ComfyUI/custom_nodes
git clone https://github.com/rh6423/ComfyUI-QuickSize.git

Restart, done. Or ComfyUI Manager → search "QuickSize" → install.

Verdict

If you've already got a resolution preset you're happy with, you don't need this. If you're still wrestling SD1.5 workflows from the archive and your muscle memory is "type 768×768 and hope," this is a genuine quality-of-life upgrade - just remember the 9:16 shortcut is a square in disguise. The pack author (rh6423) deliberately kept these per-model and simple; this node is the one where that minimalism hides a small landmine.