Sprite Sheets

Overview

Sprite sheets (also called texture atlases) combine multiple animation frames or sprites into a single image file. This technique is essential for game development, reducing draw calls and improving performance.

Aseprite can automatically generate optimized sprite sheets with accompanying data files for various game engines and frameworks.

Accessing Sprite Sheet Export

Open the Export Dialog

Navigate to File → Export → Export Sprite Sheet or press Ctrl+E (Windows/Linux) or Cmd+E (macOS).

Configure Layout

Choose your sprite sheet layout type and constraints.

Set Export Options

Configure borders, padding, and frame selection.

Export

Choose output file and optional data file format.

Layout Types

Horizontal
Vertical
Packed
By Layers/Tags

Frames arranged in rows

[Frame1][Frame2][Frame3][Frame4]
[Frame5][Frame6][Frame7][Frame8]

Options:

Fixed number of columns
Maximum width constraint
Auto-wrap to next row

Best for animations with consistent frame sizes.

Frames arranged in columns

[Frame1] [Frame5]
[Frame2] [Frame6]
[Frame3] [Frame7]
[Frame4] [Frame8]

Options:

Fixed number of rows
Maximum height constraint
Auto-wrap to next column

Optimized rectangle packing

[Large Frame 1    ][Sm1][Sm2]
[Large Frame 1    ][Sm3][Sm4]
[Medium Frame 2][Frame 3  ]

Benefits:

Minimal wasted space
Efficient texture memory usage
Automatic bin packing algorithm
Different sized sprites

Packed layout is ideal for sprites with varying dimensions.

Layout Constraints

Fixed Columns

Specify exact number of columns

Columns: 4
Result: 4 frames per row

Fixed Rows

Specify exact number of rows

Rows: 3
Result: 3 frames per column

Max Width

Maximum sprite sheet width

Max Width: 2048px
Frames wrap at width limit

Max Height

Maximum sprite sheet height

Max Height: 2048px
Frames wrap at height limit

Padding & Borders

┌─────────────────────────────┐ ← Border Padding
│  ┌────┐  ┌────┐  ┌────┐    │
│  │ F1 │  │ F2 │  │ F3 │    │
│  └────┘  └────┘  └────┘    │
│    ↑       ↑                │
│    │       └─ Shape Padding │
│    └───────── Inner Padding │
└─────────────────────────────┘

Border Padding

Empty space around the entire sprite sheet edge.Range: 0-100 pixelsUse cases:

Prevent edge bleeding in 3D engines
Create safe margins
Avoid texture filtering artifacts

Shape Padding

Space between individual frames/sprites.Range: 0-100 pixelsUse cases:

Prevent UV bleeding
Visual separation
Easier manual editing

Use 1-2 pixels of shape padding to prevent texture bleeding in most game engines.

Inner Padding

Padding inside each frame boundary.Range: 0-100 pixelsUse cases:

Consistent frame spacing
Alignment adjustments

Extrude

Extends the edge pixels outward into padding.Benefits:

Eliminates edge artifacts
Perfect for 3D texture mapping
Prevents transparent gaps

Extrude repeats the edge pixel color into the padding area to prevent texture sampling issues.

Frame Selection

All Frames
By Tag
Selected Frames
By Layer

Export every frame in the sprite.

Frame: 1, 2, 3, 4, 5, ..., N

Export frames within a specific animation tag.

Tag: "walk"
Frames: 10-17

Tags allow you to export specific animations separately.

Only export frames selected in the timeline.

Selection: 1, 3, 5, 7
Result: Only selected frames

Optimization Options

Trim Sprite

Remove empty space around entire spriteCrops transparent pixels from canvas edges

Trim Cels

Remove empty space per frameEach frame individually cropped

Ignore Empty

Skip completely transparent framesReduces sprite sheet size

Merge Duplicates

Reuse identical framesSignificant size reduction for loops

Important: Trimming frames may result in different frame sizes, which can complicate rendering in some game engines.

Data File Formats

Sprite sheet metadata can be exported in various formats:

JSON
JSON Array
CSS
XML

{
  "frames": [
    {
      "filename": "sprite 0.aseprite",
      "frame": { "x": 0, "y": 0, "w": 32, "h": 32 },
      "rotated": false,
      "trimmed": false,
      "spriteSourceSize": { "x": 0, "y": 0, "w": 32, "h": 32 },
      "sourceSize": { "w": 32, "h": 32 },
      "duration": 100
    }
  ],
  "meta": {
    "app": "https://www.aseprite.org/",
    "version": "1.3",
    "image": "sprite.png",
    "format": "RGBA8888",
    "size": { "w": 256, "h": 128 },
    "scale": "1"
  }
}

JSON format is widely supported by game engines and frameworks.

[
  {
    "filename": "sprite 0.aseprite",
    "frame": { "x": 0, "y": 0, "w": 32, "h": 32 },
    "duration": 100
  },
  {
    "filename": "sprite 1.aseprite",
    "frame": { "x": 32, "y": 0, "w": 32, "h": 32 },
    "duration": 100
  }
]

Simpler array-based structure

.sprite-frame-0 {
  background-position: 0px 0px;
  width: 32px;
  height: 32px;
}
.sprite-frame-1 {
  background-position: -32px 0px;
  width: 32px;
  height: 32px;
}

Perfect for web development

<TextureAtlas imagePath="sprite.png">
  <SubTexture name="sprite 0.aseprite" x="0" y="0" width="32" height="32"/>
  <SubTexture name="sprite 1.aseprite" x="32" y="0" width="32" height="32"/>
</TextureAtlas>

Compatible with Starling, Sparrow

Advanced Features

Split Layers

Generate separate sprite sheets for each layer.Output:

character-body.png + character-body.json
character-armor.png + character-armor.json
character-weapon.png + character-weapon.json

Useful for:

Modular character systems
Customizable sprites
Dynamic layer composition

Split Tags

Generate separate sprite sheets per animation tag.Output:

sprite-idle.png + sprite-idle.json
sprite-walk.png + sprite-walk.json
sprite-attack.png + sprite-attack.json

Benefits:

Organized animations
Lazy loading
Smaller file sizes per action

Split Grid

Export grid cells as individual sprites.Useful for:

Tile-based sprites
Grid-aligned assets
Uniform cell exports

From Tilesets

Export tilemap tilesets as sprite sheets.Features:

Preserve tile indices
Include tile metadata
Optimize for tile-based rendering

Game Engine Integration

Unity
Godot
Phaser
libGDX

Recommended settings:

Format: JSON or JSON Array
Layout: Packed or Grid
Enable: Trim Cels, Merge Duplicates

Import steps:

Import PNG as Sprite (Multiple)
Use Sprite Editor to slice
Parse JSON for animation data

Use Unity’s Sprite Packer or Addressables for additional optimization.

Recommended settings:

Format: JSON
Layout: Packed
Enable: Trim Cels

Import steps:

Import PNG as texture
Create AtlasTexture resources from JSON
Use AnimatedSprite node

var frames = []
var data = JSON.parse(file.get_as_text())
for frame in data.result.frames:
    var atlas = AtlasTexture.new()
    atlas.atlas = texture
    atlas.region = Rect2(frame.frame.x, frame.frame.y, 
                        frame.frame.w, frame.frame.h)
    frames.append(atlas)

Recommended settings:

Format: JSON (Hash or Array)
Layout: Packed
Enable: Extrude

Usage:

this.load.atlas(
  'sprite',
  'sprite.png',
  'sprite.json'
);

this.anims.create({
  key: 'walk',
  frames: this.anims.generateFrameNames('sprite'),
  frameRate: 10,
  repeat: -1
});

Recommended settings:

Format: JSON or XML
Layout: Packed
Use TexturePacker compatible format

Usage:

TextureAtlas atlas = new TextureAtlas(
  Gdx.files.internal("sprite.atlas")
);
Animation<TextureRegion> animation = 
  new Animation<>(0.1f, atlas.findRegions("sprite"));

Best Practices

Power-of-Two Dimensions

Use texture sizes that are powers of 2 (256, 512, 1024, 2048) for better GPU compatibility.

Some older mobile GPUs require power-of-two textures.

Minimize Padding for Mobile

Mobile devices have limited texture memory. Use minimal padding when targeting mobile platforms.

Use Packed Layout

For varied sprite sizes, packed layout minimizes wasted texture space.

Enable Extrude

Always enable extrude to prevent edge artifacts in 3D engines and scaled sprites.

Test Different Constraints

Experiment with width/height constraints to find optimal texture dimensions for your target platform.

Texture Size Limits:

Desktop: Usually 8192x8192 or higher
Mobile: Often limited to 2048x2048 or 4096x4096
WebGL: Varies by device, typically 4096x4096

Always test on your target platform!

Command Line Export

Export sprite sheets via CLI for build automation:

aseprite -b sprite.aseprite \
  --sheet sprite-sheet.png \
  --data sprite-sheet.json \
  --format json-array \
  --sheet-type packed \
  --trim \
  --merge-duplicates

Integrate CLI export into your build pipeline for automated asset generation.

Troubleshooting

Sprite sheet too large

Solutions:

Reduce padding values
Enable trim and merge duplicates
Split by tags or layers
Reduce sprite resolution
Use packed layout

Texture bleeding between frames

Solutions:

Increase shape padding (1-2 pixels minimum)
Enable extrude option
Disable texture filtering in engine
Use premultiplied alpha

Wrong frame order in data file

Solutions:

Use filename format to control ordering
Check tag frame ranges
Verify selected frames
Use JSON format for explicit indexing

Transparent pixels appearing as black

Solutions:

Check color mode (use RGBA)
Ensure alpha channel is not premultiplied incorrectly
Verify game engine blend modes
Use PNG format for sprite sheet

File Formats

Learn about output file format options

GIF Export

Alternative animation export method

PNG Sequences

Export individual frame files

Get Started

Core Concepts

Drawing Tools

Advanced Features

Workspace

Import & Export

Overview

Accessing Sprite Sheet Export

Layout Types

Layout Constraints

Fixed Columns

Fixed Rows

Max Width

Max Height

Padding & Borders

Frame Selection

Optimization Options

Trim Sprite

Trim Cels

Ignore Empty

Merge Duplicates

Data File Formats

Advanced Features

Game Engine Integration

Best Practices

Command Line Export

Troubleshooting

File Formats

GIF Export

PNG Sequences

Get Started

Core Concepts

Drawing Tools

Advanced Features

Workspace

Import & Export

​Overview

​Accessing Sprite Sheet Export

​Layout Types

​Layout Constraints

Fixed Columns

Fixed Rows

Max Width

Max Height

​Padding & Borders

​Frame Selection

​Optimization Options

Trim Sprite

Trim Cels

Ignore Empty

Merge Duplicates

​Data File Formats

​Advanced Features

​Game Engine Integration

​Best Practices

​Command Line Export

​Troubleshooting

​Related Topics

File Formats

GIF Export

PNG Sequences

Overview

Accessing Sprite Sheet Export

Layout Types

Layout Constraints

Padding & Borders

Frame Selection

Optimization Options

Data File Formats

Advanced Features

Game Engine Integration

Best Practices

Command Line Export

Troubleshooting

Related Topics