LinuxWhat is the ORA file format?
An .ora file is an OpenRaster layered image - an open standard developed through the Freedesktop.org community with contributions from the Krita, GIMP, and MyPaint projects. Its design goal is a portable, application-neutral format for exchanging multi-layer raster artwork, serving a similar purpose to Photoshop's .psd but without vendor lock-in.
Under the hood, an .ora file is a ZIP archive containing a set of required components: a mimetype entry stored uncompressed (containing the string image/openraster), a stack.xml document describing the layer tree with blend modes, opacity, and offsets, a data/ directory holding each layer as a PNG image, a Thumbnails/thumbnail.png preview, and a mergedimage.png flattened composite. This ZIP-based packaging follows the same pattern as ODF documents.
Layers support 8-bit or 16-bit per channel RGBA color, giving a maximum of 48-bit color plus alpha. The specification is intentionally minimal, allowing applications such as Krita to add extra metadata in their own XML namespaces without breaking compatibility with other tools.
Because .ora is a ZIP container, files can be inspected with any archive utility. Krita, GIMP 2.10+, and MyPaint all read and write .ora natively. The current stable specification is version 0.0.6.
Security & safety
RISK: LOWStandard ZIP-based image format; no executable content. Parsing malformed ZIP or PNG entries is a theoretical attack surface, but no known CVEs for ORA specifically. Treat with same caution as any image file from unknown sources.
Format details
in a nutshell- Oracle Database Configuration File - Plain-text INI-style config files (tnsnames.ora, listener.ora, sqlnet.ora, spfile.ora) used by Oracle DB for network and instance configuration; edit with any text editor.
Programs that open ORA files
Windows2 apps
GIMP
Open-source File → Open, select the .ora file; layers import. Export back as ORA via File → Export As. 
macOS2 apps
Technical details
deep spec| Container | ZIP archive (magic bytes 50 4B 03 04 at offset 0) |
| Identification | mimetype entry (stored uncompressed at the start of the ZIP) must contain the string image/openraster |
| Encoding | Binary ZIP with embedded XML (stack.xml) and PNG layer files |
| Byte order | Little-endian (ZIP format) |
| MIME type | image/openraster |
| Layer encoding | PNG files per layer in the data/ directory; 8 bpc or 16 bpc RGBA |
| Compression | STORED (no compression) for the mimetype entry; DEFLATE for PNG layer data within the ZIP |
| Color depth | Up to 48-bit (16 bpc RGB) plus full alpha channel |
| Integrity | ZIP CRC-32 checksum per entry; no whole-file hash defined in the specification |
| Required archive members | mimetype, stack.xml, data/ layer PNGs, mergedimage.png (flattened composite), Thumbnails/thumbnail.png (128x128 preview) |
| Spec revision | 0.0.6 (current stable) |
| Extensibility | Application-specific XML namespaces permitted in stack.xml (e.g. Krita adds krita: attributes without breaking other tools) |
| Encryption | Not defined in the OpenRaster specification |
| Released | 2008 (initial draft specification) |
| Latest version | OpenRaster spec 0.0.6 (current stable) |
| Open standard | Yes · royalty-free |
| Specification | www.openraster.org |
ORA conversions
Community Q&A
asked by usersNo questions yet - be the first to ask about ORA files.
