What is a .ora file? (OpenRaster)

An .ora file is OpenRaster, an open, application-neutral format for layered images. It was created so painting programs like Krita, MyPaint and GIMP could exchange layered artwork without a proprietary format.

What is a .ora file used for?

OpenRaster is a ZIP package of PNG layers plus a stack description, so it starts with the ZIP signature and any tool can read it. It is the open answer to PSD for interchange between free painting apps.

Krita, GIMP and MyPaint all read and write .ora. Export to PNG for a flat image.

How to open a .ora file

The .ora format opens in the following apps, grouped by operating system. If one app does not work, try another from the same list. For a step-by-step walkthrough, see how to open a .ora file.

Windows

Krita
GIMP
MyPaint

macOS

Krita
GIMP

Linux

Krita
GIMP
MyPaint

How to convert a .ora file

You can convert a .ora file to png, psd, kra using a conversion tool or the export menu of an app that opens it.

.ora file signature (magic bytes)

Programs recognise a .ora file by the bytes at the start of the file, not by its name. These are the signatures for OpenRaster. For a full breakdown, see the OpenRaster file signature page.

Hex signature	Offset	Note
50 4B 03 04	0	ZIP package (PK..)

See the full magic-numbers reference for every format.

Frequently asked questions

What is a .ora file?

How do I open an .ora file?

Use Krita, GIMP or MyPaint, all free and all supporting OpenRaster with layers intact. Export to PNG for a flat image.

What is OpenRaster for?

Exchanging layered artwork between free painting programs without relying on the proprietary PSD format. It is an open, ZIP-based standard.

Is .ora the same as .psd?

Both store layered images, but .ora is an open ZIP-of-PNG format, while .psd is Adobe's proprietary Photoshop format.

Related formats

Sources

Details on this page were checked against authoritative references:

OpenRaster specification