Sif Format

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A ".sif" file is the XML representation of a canvas. It holds the canvas's metadata, such as width and height, as well as information about its layers. Typically, a Synfig production comprises many .sif files joined in a sequence or nested within each other.

The .sif format is formidably complex and evolving. It is implementation-defined rather than spec-defined. Therefore, you should take everything on this page with a grain of salt. Indeed, the implementation can change at any point.

There are no plans to freeze the format.

Source code

The .sif format is implemented by the following file:


Linking / Exporting

.sif files aren't always self-contained. They can link to parts of other .sif files, which creates a dependency of one on the other. This may seem strange to animators who use Flash because, in Flash, animation files are usually self-contained.

One drawback of Synfig's approach is that .sif dependencies are hard to track. A tool called RenderChan solves this problem.


Recursion of .sif files is prohibited.


Synfig recognizes ".sifz" as the extension of gzip-compressed .sif files. New and alternate implementations of .sif are urged to support this compression, although it is not required.

Synfig recognizes the ".sfg" file format as an archival file format. A .sfg is a ZIP archive that bundles a .sif and its resources together. In Synfig Studio, images and sounds can be packed using Import Image Layer or Sound Layer.



The top element of a .sif file is always a <canvas>.

<?xml version="1.0"?>

<canvas version="0.1" width="300" height="350" xres="2952.7559"
        yres="2952.7559" view-box="-1.5 2.5 1.5 -1" antialias="2"
        fps="12" begin-time="0f" end-time="0f" bgcolor="0.5 0.5 0.5 1">
Attribute Default What it is
version no default, this attribute is required 0.1, always
width 480 the width of the canvas in pixels
height 270 the height of the canvas in pixels
xres 2835 the width of the canvas in pixels per meter
yres 2835 the height of the canvas in pixels per meter
view-box -4 2.25 4 -2.25 the bounding coordinates of the canvas (left top right bottom)
antialias 2 how hard Synfig should try to antialias the image
fps 24 frames per second
begin-time 0 where on the timetrack should rendering start
end-time 0 what on the timetrack should rendering end
bgcolor 0.5 0.5 0.5 1.0 the color of the background in RGBA
focus 0 0 the anchor point for changing the view-box

Inside a <canvas> you can find the following elements:

  • <name>
  • <meta>
  • <author>
  • <desc>
  • <layer>
  • <defs>
  • <bones>
  • <keyframe>


The short name of the canvas.

<canvas version="0.1">
    <name>Aqua Sphere</name>


Metadata for the Synfig Studio editor. These can be safely ignored by other implementations.

<canvas version="0.1">
    <meta name="grid_show" content="1" />

Synfig Studio recognizes these <meta> names (source):

  • grid_size
  • grid_color
  • grid_snap
  • grid_show
  • onion_skin
  • onion_skin_past
  • onion_skin_future
  • guide_color
  • guide_snap
  • guide_show
  • guide_x
  • guide_y
  • sketch
  • solid_lines
  • background_size
  • background_first_color
  • background_second_color


The name of the canvas's author.

<canvas version="0.1">
    <author>King Arthur</author>


A human-readable description of the canvas.

<canvas version="0.1">
    <desc>This aqua-colored sphere reminds me of something from Mac OS X.</desc>



Layers describe the shapes and effects on a canvas.

<canvas version="0.1">
    <layer type="solid_color" version="0.1"
Attribute Default What it is
type no default see the list of types
version no default depends on the layer type
group the name of the group that this layer belongs to
desc a human-readable description
active true whether the layer is selected (?)
exclude_from_rendering false whether it should be rendered

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