Pixel Art Upscaler Without AI — Integer Nearest 1× to 8×
For store pages, trailers and social posts, pixel art has to be enlarged without blur. An integer nearest-neighbour scale turns each pixel into an exact N×N block; the output size is shown before you save.
- PNG framesMeasured· Pillow
- PaletteMeasured· re-import
- pixel-lab.jsonUNVERIFIED
What it does
- Integer scales 1× to 8× with nearest-neighbour only: no filter, no generated detail.
- The checker detects whether the image is already an upscale (exact scale and offset), so you do not scale a scaled image.
- If an exact grid is found, recover the 1× source first and scale that.
- Works per frame for animations; export PNG.
How to do it
- Drop the image or frames.
- Read the scale report; recover 1× if it is already scaled.
- Pick the integer scale.
- Export the PNG.
Outputs and how each was checked
"Measured" means the downloaded file was opened again outside the page (Pillow, numpy or an independent parser) and the property was measured. Loading these files in a game engine was not tested.
| Target | Files | Check |
|---|---|---|
| PNG frames | anim_N.png · 1×–8× nearest | Measured PillowEvery exported colour re-read from the PNGs lies inside the locked palette. |
| Palette | .gpl · .hex (Lospec) · .json | Measured re-importEach format was exported and imported back through the UI: 16 → 16 colours. |
| pixel-lab.json | generic frames + palette | UNVERIFIEDGeneric JSON; not loaded in any engine. |
Evidence
8 anti-aliased frames → one 16-colour palette with 0 exported colours outside it; an unchanged region identical in all 8 frames with dithering off and with Bayer 4×4; the anti-alias remover took 271 colours to 16 without moving a single silhouette pixel; integer scale, offset and 2.5× non-integer scaling detected exactly.
Limits
- Frames larger than 4096 × 4096 are refused: every pass runs on the main thread, and there is no cancel button yet.
- A sprite sheet is treated as one image; cut it into frames first (sprite sheet cutter).
- With a dithering mode on, the cleanup counts include dither pixels; set dithering to None first.
- The exported JSON is generic; importing it into Godot or Unity was not tested.
Questions
Why only whole numbers?
A non-integer scale makes some pixels wider than others. The checker measures that too: a 2.5× nearest resize reads 2.500× and is not called integer.
Does it add detail like AI upscalers?
No. Every output pixel is a copy of a source pixel.
Is it free, and do I need an account?
Everything on these pages is free and works without an account. There is no watermark and no export that is held back.
Are my sprites uploaded?
No. The Studio decodes, packs and exports in this browser tab. Projects are autosaved in the browser (IndexedDB) and can be saved as a .nerulio file.
Does it need Aseprite or an engine plugin installed?
No. .aseprite files are read and written in the browser, and each engine bundle carries what that engine needs (for Godot, the import settings and scene; for Unity and the Godot TileSet, a small editor script).