What is the RTP file format?
.rtp is a binary delta patch package produced by RTPatch Professional, a commercial patching tool developed by Pocket Soft Inc. Rather than distributing a full replacement file, an .rtp file stores only the binary differences between an old and a new version of a file, dramatically reducing distribution size.
Microsoft adopted the RTPatch format for early Windows and MS-DOS software updates. Under MS-DOS, the companion executable PATCH.EXE applied .rtp files to update system components. Windows 3.x included an automated update service that consumed these patch packages.
The format is proprietary and closed - Pocket Soft never published a specification. Files are binary packages with no publicly documented magic bytes, containing compressed delta data along with integrity verification of the patched output.
By the Windows XP era, Microsoft had migrated to Windows Update infrastructure, MSP patches, and .msu packages, rendering .rtp files effectively obsolete. Modern Windows has no built-in handler for .rtp files. The format is now mainly encountered when working with archived MS-DOS or Windows 3.x/95/98 software.
Security & safety
RISK: LOWHistorical patch files pose no practical risk on modern systems since no modern software will execute them. If encountered on a contemporary system as an unexpected download, scan for malware - the .rtp extension could be used by malware as an unusual extension to evade signature detection.
Format details
in a nutshell- Real-time Transport Protocol session descriptor - Some streaming applications use .rtp for RTP (RFC 3550) session/payload descriptor files - unrelated to the Microsoft patch format.
- RPG Maker RTP resource pack - RPG Maker 2000/2003 uses .rtp as an abbreviation for 'Run-Time Package' - a resource bundle; installed as a folder, not a single .rtp file.
Programs that open RTP files
Windows1 app
RTPatch (historical, Pocket Soft)
Paid Historical tool only; PATCH.EXE for DOS or the Windows update service applied .rtp patches automatically. No modern equivalent. Technical details
deep spec| Format type | Binary delta/patch package |
| Encoding | Binary |
| Byte order | Little-endian (x86 era) |
| Container | Proprietary RTPatch binary container |
| Delta algorithm | Binary diff of old vs new file content |
| Integrity | Checksum verification of patched output |
| Typical file size | 10 KB - 5 MB |
| Application tool (DOS) | `PATCH.EXE` |
| Producing software | RTPatch Professional (Pocket Soft Inc.) |
| Target OS | MS-DOS, Windows 3.x, Windows 95, Windows 98, Windows NT |
| Superseded by | `.msp`, `.msu`, and Windows Update infrastructure (post-2000) |
| Released | Early 1990s (MS-DOS / Windows 3.x era) |
Community Q&A
asked by usersNo questions yet - be the first to ask about RTP files.
