OXPS vs XPS: What's the Difference?
If you have a file with a .oxps extension and another with a .xps extension, you might assume they're completely different formats. They're not — they're closely related, and most readers handle both. This guide explains the distinction.
Short answer
- XPS — Microsoft's original proprietary version, introduced in Windows Vista (2006).
- OXPS — the open standard version (ECMA-388 and ISO/IEC 29500-2, finalised 2009). Used as the default by Windows 8 and later.
- Practical difference for users: almost none. Files are the same kind of fixed-layout document. The internal package format and a few namespaces differ.
Our converter handles both .xps and .oxps input. Most third-party readers and converters do too.
The history (briefly)
Microsoft launched XPS as a competitor to PDF in 2006. To improve cross-platform credibility, the format was submitted to ECMA International and standardised as ECMA-388 in 2009. The standardised version was renamed OpenXPS (OXPS) to avoid trademark issues.
From Windows 8 onward, the built-in XPS Document Writer began outputting files with the .oxps extension by default. Files created on Windows 7 and earlier kept the .xps extension. So the file extension you see is mostly an indication of which Windows version generated the file, not a fundamental format difference.
Internal differences
| Aspect | XPS (proprietary) | OXPS (ECMA-388) |
|---|---|---|
| Container | Open Packaging Conventions ZIP | Same OPC ZIP container |
| Default extension | .xps | .oxps |
| Namespaces | Microsoft URIs (e.g. schemas.microsoft.com/xps/2005/06) | OASIS / ECMA URIs (e.g. schemas.openxps.org/oxps/v1.0) |
| Standard | De facto, Microsoft-controlled | ECMA-388 / ISO/IEC 29500-2 (open) |
| Document model | FixedDocumentSequence | FixedDocumentSequence (same) |
Will my XPS reader open OXPS (and vice versa)?
Mostly yes. Modern Microsoft XPS Viewer, Foxit Reader, and most online converters (including ours) treat them as the same format. A few older or strictly-conformant readers reject the "wrong" extension — in which case renaming the file from .oxps to .xps often makes the reader accept it (the underlying bytes are nearly identical).
How to convert OXPS or XPS to PDF
Both formats are handled by XPS2PDF.co.uk. Just upload the file — we automatically detect XPS vs OXPS and convert either to PDF (or JPG). No account, no watermark, files deleted within 60 minutes.
Frequently asked questions
Can I just rename a .oxps file to .xps?
Often yes, and many users get away with it. The file structure is close enough that renaming works for most readers. But it's a hack — for a robust conversion, use a tool that understands both formats.
Why does Windows 8+ default to OXPS instead of XPS?
OXPS is the open standard version and Microsoft wanted to align with the published ECMA spec rather than a proprietary variant. The change made OXPS the official "go-forward" extension on Windows.
Are there any tools that produce OXPS but can't read XPS?
The XPS Document Writer on Windows 8+ produces OXPS but reads both. We're not aware of any modern reader that handles only one of the two — the formats are close enough that supporting both is trivial.
Last updated: April 2026