ASEPRITE ファイル形式とは？
An .aseprite file is the native project format of Aseprite, an animated sprite editor and pixel art tool from Igara Studio. Instead of a single flat picture, it stores a full sprite: multiple animation frames with their durations, layers and layer groups, blend modes, the color palette, animation tags, and slices. Aseprite supports RGBA, grayscale, and indexed color, and version 1.3 added tilemaps and tilesets to the same file.
Internally the format is binary and little-endian. It opens with a 128-byte header carrying the magic number 0xA5E0, the frame count, canvas size, and color depth, followed by one block per frame. Each frame holds typed chunks for layers, cels, palettes, tags and slices, and the pixel data inside each cel is DEFLATE-compressed. The .ase extension is the identical format under a different name, so the two are interchangeable.
セキュリティと安全性
リスク： LOWAn .aseprite file is passive image data with no scripting or macro capability, so simply opening one cannot execute code. The only realistic risk is a malformed file triggering a parser bug in older editor builds. Keep Aseprite or LibreSprite updated and obtain files from sources you trust.
形式の詳細
概要正式名称Aseprite Sprite File別名 ASE file, Aseprite Sprite
開発元Igara Studio S.A. (David Capello)登場時期 2001 (Aseprite); documented .ase/.aseprite format c. 2016
カテゴリプラグインファイル
MIME タイプapplication/octet-stream
タイプBinary, chunk-based (little-endian)
この拡張子は以下でも使用されています…
- Adobe Swatch Exchange (.ase) - The related
.aseextension is also used by Adobe for color swatch libraries, an unrelated palette format. This is a different file type from an Aseprite sprite.
マジックバイト ・ ファイルシグネチャ
オフセット
0405
16進数
A5E0
ASCII
··
The file starts with a 4-byte DWORD file size, then a 16-bit WORD magic number 0xA5E0 (stored little-endian as bytes E0 A5) at offset 4. There is no signature at offset 0.
ASEPRITE ファイルを開くプログラム
Windows3 apps
Aseprite
有料 Open the .aseprite file directly to edit every layer, frame and tag in its native editor.
LibreSprite
オープンソース Open .aseprite and .ase files for free in this GPLv2 fork of the last open-source Aseprite release.
Aseprite CLI
有料 Run aseprite -b sprite.aseprite --save-as out.png to batch-open and export files from a script. 
macOS2 apps
Aseprite
有料 Open the .aseprite file to edit the sprite with full layer, frame and palette data preserved. 
Linux2 apps
Aseprite
有料 Open the file natively, or compile Aseprite from source under its EULA for personal use.
LibreSprite
オープンソース Install from Flatpak or your package manager and open .aseprite/.ase files free of charge.
Web1 app
Aseprite Wizard (Godot plugin)
オープンソース Import .aseprite files into a Godot project as AnimatedSprites or SpriteFrames without a manual export step. 技術的詳細
詳細仕様| Encoding | Binary |
| Byte order | Little-endian (Intel) |
| Container | Header (128 bytes) followed by frames, each holding typed data chunks (layers, cels, palettes, tags, slices, tilesets) |
| Compression | Per-cel raster data is zlib/DEFLATE compressed (compressed image cel type); raw and linked cel types also exist |
| Typical size | A few KB to several MB depending on canvas size, frame count and layers |
| Structure | DWORD file size, WORD magic 0xA5E0, then header fields: frame count, width, height, color depth (32 bpp RGBA, 16 bpp grayscale, 8 bpp indexed), flags, palette info. Each frame begins with a 16-byte frame header (magic 0xF1FA) and a chunk count, followed by chunks such as 0x2004 layer, 0x2005 cel, 0x2019 palette, 0x2018 tags, 0x2022 slice, 0x2023 tileset. |
| Platforms | Windows, macOS, Linux |
| Color Modes | RGBA (32 bpp), Grayscale (16 bpp), Indexed (8 bpp, up to 256 colors) |
| Notes | The .aseprite and .ase extensions are identical in content; Aseprite defaults to .aseprite. The format keeps all editing data intact: layers, layer groups, blend modes, frames, frame durations, timeline, palette, tags, slices, and (in 1.3+) tilemaps and tilesets. |
| リリース日 | 2001 (Aseprite); documented .ase/.aseprite format c. 2016 |
| 最新バージョン | Aseprite 1.3.x file format |
| 仕様書 | github.com |
ASEPRITE の変換
可能
.ASEPRITE .PNGガイド
はい - Aseprite でスプライトを開き、単一の PNG の場合は «File > Export > Export As» を、すべてのフレームを1枚にまとめる場合は «Export Sprite Sheet»…
変換方法
.ASEPRITE .GIFガイド
はい - Aseprite で «File > Export > Export As» を使用し、ファイル名を .gif にすることで、アニメーションをアニメーション GIF に変換できます。
変換方法
.ASEPRITE .JSONガイド
はい - «--data» オプション（または «Export Sprite Sheet» ダイアログの «JSON Data» チェックボックス）を使用してスプライトシートをエクスポートすると、Aseprite…
変換方法
.ASEPRITE .BMPガイド
はい - Aseprite でスプライトを開き、File > Export > Export As（または File > Save As）で拡張子を .bmp にして保存することで、Windows Bitmap…
変換方法
コミュニティ Q&A
ユーザーからの質問まだ質問はありません。ASEPRITE ファイルについて最初の質問をしてみましょう。
よくある質問
How do I open a .aseprite file?
Open it in Aseprite, the program that created it, on Windows, macOS or Linux. If you do not own Aseprite, the free open-source fork LibreSprite reads the same files.
Is .aseprite the same as .ase?
Yes. The two extensions use an identical binary format. Aseprite treats them as interchangeable and saves as
.aseprite by default; you can rename one to the other safely.Can I open a .aseprite file without buying Aseprite?
Yes. LibreSprite opens
.aseprite and .ase files for free, and several game-engine plugins and libraries (for Godot, Unity, Rust, and others) can read the format directly using the published specification.How do I convert a .aseprite file to PNG or GIF?
In Aseprite use File > Save Copy As and choose
.png or .gif, or File > Export Sprite Sheet for a packed atlas. From the command line, aseprite -b file.aseprite --save-as out.png does the same.Why won't my image viewer open a .aseprite file?
It is a layered project format, not a plain picture, so standard viewers do not recognize it. Export a copy to
.png or .gif if you need to view or share the artwork elsewhere.Does a .aseprite file keep my layers and animation?
Yes. It preserves color mode, layers, layer groups, blend modes, every frame and its duration, the palette, animation tags, and slices, which is why it is the format to keep as your master file.
参考文献
1Aseprite - Wikipediaen.wikipedia.org
2Aseprite File Format Specs (official, GitHub)github.com
