Pixel Art Editor Online — Draw Sprites in Your Browser
A pixel editor for game sprites that opens in a browser tab: the pencil, bucket, shapes, selections and layers you know from Aseprite, on the same project as the Studio's animation, packing and engine exports. Nothing is installed and your pictures never leave the device.
- .asepriteVerified· Aseprite 1.3.18
- Palette filesMeasured· read back
- Engine bundlesVerified· Godot 4.7.2 · Unity 6000.5
- Frame PNG · .nerulioPlain files
What it does
- Eleven tools on Aseprite's keys: pencil (B), eraser (E), bucket (G), eyedropper (I), line (L), rectangle and ellipse (U, Shift+U), marquee (M), lasso (Q), magic wand (W) and move (V). Brushes are square or round, 1 to 16 px, changed with [ and ].
- Pixel-perfect strokes are on by default: the L-shaped corners a freehand stroke leaves on a staircase are removed as you draw. Shift+click draws a straight line from the last point; Shift on the line tool snaps to pixel-art angles.
- Inks for shading work: alpha compositing, lock alpha, shading along a selected palette ramp (right button steps the other way) and dither patterns (Bayer 2, 4 and 8, checker, rows, columns) with a density setting.
- Layers with visibility, lock, opacity and the 19 Aseprite blend modes, computed with Aseprite's own blend maths; merge down, duplicate and reorder. Symmetry vertical, horizontal or both, with the axis position typed in.
- Every stroke, fill, move, flip, palette edit or layer change is exactly one entry in History. Projects autosave in the browser and save as a .nerulio file; .aseprite and PNG export are in the Pixel menu.
How to do it
- Drop a PNG, numbered frames, a GIF or an .aseprite file on this page, or open the empty Pixel workspace and start a new sprite (size, RGB or indexed).
- Pick the pencil with B; left button paints the foreground colour, right button the background colour, and X swaps them.
- Add a layer with Shift+N for shading, set its blend mode in the Layers panel and lock the line-art layer so it cannot be painted by accident.
- Save the .aseprite from the Pixel menu to keep layers and palette, or open Pack & Export when the sprite is ready for Godot, Unity or Phaser.
Aseprite keys that work in the Pixel workspace
Press ? in the Studio for the full list. These are the ones used most while drawing.
| Key | Tool or command | Note |
|---|---|---|
| B / E / G | Pencil / eraser / bucket | Bucket: contiguous or global, tolerance, sample all layers |
| L / U / Shift+U | Line / rectangle / ellipse | Shift snaps lines to pixel-art angles and makes squares or circles |
| M / Q / W | Marquee / lasso / magic wand | Shift adds, Alt subtracts, Shift+Alt intersects |
| Ctrl+C / X / V | Copy / cut / paste | Pasted pixels float: arrows nudge 1 px, Enter drops, Esc cancels |
| Shift+N / Ctrl+J / Ctrl+E | New layer / duplicate / merge down | Merge down keeps every frame where either layer has a cel |
| [ / ] | Brush size 1–16 | Square or round tip |
Engine exports and how each was checked
"Verified" means the exported files were loaded by the real engine or tool on real CC0 assets and the result was compared with the source. Anything that was not loaded is labelled as such.
| Target | Files | Check |
|---|---|---|
| .aseprite | layers · blend · opacity · locked · indexed palette · frames · tags | Verified Aseprite 1.3.18The real Aseprite command line reopened the file as INDEXED with 2 layers, Multiply at opacity 160 and the locked layer not editable; the frames are pixel-identical. |
| Palette files | .gpl · .pal · .hex · .ase · .act · .json | Measured read backEach format was written and read back identical; Aseprite's own .gpl, .pal, .hex and .act and a real Adobe .ase (16 colours) were read. |
| Engine bundles | Godot 4 · Unity 6 · Phaser 3/4 · PixiJS 8 … through Pack & Export | Verified Godot 4.7.2 · Unity 6000.5The sprite you drew is packed in Pack & Export; those engine files were loaded in each engine on real CC0 assets (47 of 49 runs pass; the 2 failures are a Phaser 3.90 bug the Phaser 3 preset avoids). |
| Frame PNG · .nerulio | PNG-8 with the palette when an indexed frame fits it · project file | Plain filesPlain files for any tool; no engine run is claimed for them. |
Evidence
Cleanup benchmark, 69 CC0 cases with a known 1× original: the exact size found for 81 % (±1 px: 90 %) and 74.0 % of pixels exact with the background kept; the best competitor found 30 % of sizes (perfectPixel) and the best exact-pixel score was 44.6 % (unfake.js). An Aseprite-made ×4 nearest upscale came back 100 % exact and a ×3.78 bilinear resize 99.7 %, both with the size found automatically. A 1 px outline and a drop shadow matched Aseprite pixel for pixel (1846 and 705 px). .aseprite files written here reopen in Aseprite 1.3.18 as indexed, with their layers, blend mode and lock.
Limits
- Not in the Pixel workspace (Aseprite has them): layer groups, linked cels, tilemap layers, reference layers, RotSprite and free rotation or scaling of a selection (only flips and 90°), gradient, spray, contour and text tools, custom brushes (square or round, 1–16 px), tiled drawing, Lua scripting and a command line.
- The symmetry axis is typed, not dragged on the canvas. On touch there is no right button, so the background colour needs the swap button or X.
- Cleanup: JPEG input comes back close (84 % of pixels within ΔE 0.02 with the background kept) but rarely exact (12 %); simulated generated art gets the exact size 20 % of the time (±1 px: 80 %); none of 7 real generated images was snapped automatically — you type the pixel size the panel suggests.
- Indexed conversion picks the nearest colour in Oklab, not Aseprite's RGB distance: 68 % of the test sprite's pixels got a different (perceptually closer) pick. The Lospec search is the only network request and asks first.
Questions
Does it work with Aseprite shortcuts?
The main ones, yes: B, E, G, I, L, U, M, Q, W and V pick the same tools, X swaps colours, Shift+N adds a layer, Ctrl+E merges down, Shift+H and Shift+V flip, and Enter, F3 and F7 play, show onion skin and open the preview window. There is no screen for remapping keys yet.
How big can a sprite be before painting slows down?
In a test with a 512×512 sprite of 100 frames, a stroke refreshed only its dirty rectangle (about 0.03 ms per refresh), committing a stroke took 21 to 25 ms and switching frames 16 ms, measured in headless Chromium.
Can I use it on a phone?
At phone width the panels open as a bottom sheet (Colour, Palette, Layers, Cleanup, Audit, Timeline, History) and a tap paints one pixel. Touch has no right button, so use the swap button or X for the background colour; two-finger gestures are not covered by tests.
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).