.ui Qt Designer interface document
Documents & office
| MIME type | application/x-designer application/x-gtk-builder |
|---|---|
| Description | Qt Designer interface document |
| Category | Documents & office |
| Signature (magic bytes) | 3C 55 49 20 (<UI )3C 75 69 20 (<ui ) |
| Based on | application/xml |
Frequently asked questions
What is a .ui file?
The .ui extension is used for several formats: Qt Designer interface document (application/x-designer) and GTK+ Builder interface document (application/x-gtk-builder).
How do I open a .ui file?
With an office suite: LibreOffice (free, Windows/macOS/Linux) opens most document formats, as do Microsoft Office or the vendor’s own app.
How can you tell a genuine .ui file?
By the bytes at the start of the file, the signature (magic bytes): 3C 55 49 20 (<UI ) and 3C 75 69 20 (<ui ). On Linux and macOS, file --mime-type example.ui checks the real type regardless of the extension.
Which format is .ui based on?
Technically a .ui file is a subtype of “XML document” (application/xml), so programs for that base format can often read it too.
Which MIME type belongs to .ui?
The MIME type is application/x-designer. In the Apache web server: AddType application/x-designer .ui; in nginx: types { application/x-designer ui; }.