The Open Cel Animation format

OCA is an open format to ease the exchange of traditionnal/frame-by-frame/cel animation between different applications.


  • OCA has to be open and simple: it must be easy to implement an exporter or importer in any application providing a scripting API.

  • As it relies on existing and standard file formats (images and json/text files) stored in a simple folder, the OCA format can be imported in any application manually, even if the application does not directly support it.

  • OCA stores the most common features used by drawing/animation software: layers, groups, blending modes, animation exposure (x-sheet), etc.



We’re providing some implementations of OCA as add-ons for a few applications. If the application you need is not listed, you can politely ask for it in a feature request and we’ll consider it.

Application Add-on name Exporter Importer Comments
Krita OCA for Krita icon icon
Adobe Photoshop OCA for Photoshop icon icon
TVPaint OCA for TVPaint icon icon
Adobe After Effects DuIO icon icon
Blender OCA for Blender icon icon

icon | Available
icon | In development
icon | Planned
icon | Not supported


The OCA format is made to be simple to export/import in any application and it should not be difficult to implement it/write your own script for your application.


OCA supports the most common features of all drawing/animation software:

  • Layers
  • Layer Groups (and pass through mode if any)
  • Layer Labels
  • Layer Visibility
  • Layer Blending Modes
  • Layer Alpha options (inherit alpha)
  • Keyframes and their duration (animation exposure)
  • Opacity Keyframes
  • Layer Sizes and Coordinates
  • Document background color
  • Document color depth
  • Duration
  • Framerate

All these properties are stored in a simple JSON file, and the images are stored in standard image file formats: PNG, EXR, SVG

Everything is assembled in a folder which name ends with .oca. The JSON file is at the root, while the images are stored in subfolders corresponding to layers and groups.


JSON Objects




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Copyright (C) 2020 Nicolas Dufresne and Contributors.
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