File extension
.kra
Krita document (KRA)
.kra files are Krita documents: the native layered painting format of the Krita digital painting application, stored as a ZIP archive.
Known meanings
Formats and reference material for .kra
Krita document (KRA)
Native layered document format of Krita, a ZIP package with XML and layer data
Details
Format notes
KRA
KRA is the native file format of Krita, a free and open source painting program. It preserves everything Krita can edit, including multiple layers, masks, filter and vector layers, animation frames, color profiles, and document metadata, so it is the format to use for working files, while flattened formats such as PNG or JPEG are used for sharing.
Technical Structure
A KRA file is a ZIP archive. Following the OpenDocument-style convention,
the first entry is an uncompressed mimetype file containing
application/x-krita. The archive also contains maindoc.xml, which describes
the image size, color space, and layer stack, documentinfo.xml with
metadata, and a folder with the data for each layer. Layer pixel data uses
Krita’s own tiled format. A mergedimage.png holds the flattened image and a
preview.png holds a thumbnail, so other tools can display the content
without decoding the layers.
Adoption And Tooling
Krita reads and writes KRA on Windows, macOS, and Linux. Some other applications can import it, and file managers and thumbnailers can use the embedded preview. Because the container is a ZIP file, a KRA file can be inspected with common archive tools.
Preservation Notes
For long-term storage, keep the KRA together with a flattened export such as PNG, since only Krita fully interprets the layer structures and some features depend on the Krita version. Record the Krita version, color space, and bit depth. As with any ZIP-based format, readers should guard against oversized or malformed entries when handling untrusted files.
Further Reading
- Krita manual, KRA format:
https://docs.krita.org/en/general_concepts/file_formats/file_kra.html