Exporting and Importing Canvas Content

When you want users to save their work or share their creations, you need to export and import the canvas content. In Konva.js, the two main approaches are serialization—to save the canvas state as data—and image exporting to create a visual snapshot.

Serialization involves converting the entire canvas, including all shapes, layers, and their properties, into a format that can be easily stored or transferred. The most common format for this task is JSON. When you serialize a Konva.js stage, you call the stage.toJSON() method, which produces a string representing the complete state of the canvas. This JSON can later be loaded using Konva.Node.create(jsonString, container), fully restoring the canvas to its previous state, including all shapes, positions, and properties.

Exporting the canvas as an image is useful when you want to share or download a visual representation. Konva.js allows you to export the canvas as PNG or JPEG by using the stage.toDataURL() method. This creates a data URL that can be used as the src for an <img> tag or as a download link.

To see how these concepts work in practice, review the following example. You will find an HTML file that demonstrates how to export the current canvas as an image and how to import from a saved JSON string.