What is the SPB file format?
Files with the .spb extension are mission saves associated mainly with Flight Simulator games developed by Microsoft. The files store condition data for a flight mission, including scenario properties and other simulation-related data.
.spb files can refer to a range of compatible simulators because they are not generated directly by the game but by Microsoft ESP - a platform for generating maps and scenes of flight simulation. ESP-based content is shared across Flight Simulator X, later editions, and third-party add-ons that build on the same toolchain.
The structure of .spb files is rooted in XML - authored as standard SimProp XML documents - but the final file produced by the ESP tools is stored in SimProp Binary (compiled binary) format. This proprietary binary layout has no publicly documented constant magic bytes. An .spb file can be decompiled back to its original .xml source using the spb2xml command-line tool, which makes the content editable in any text editor. The Microsoft Flight Simulator SDK in Dev Mode also provides project editor tools that facilitate building and packaging .spb files.
Related file types used alongside .spb include .flt (saved flight state) and .spba (SimProp Binary Archive bundles for packaging multiple assets).
Security & safety
RISK: MEDIUMFlight-sim .spb files are game data, but add-on missions are downloaded from third-party sites and can ship alongside scripts/executables - install only from reputable flight-sim communities and scan downloads. spb2xml is a community tool; get it from a known flight-sim download portal. For the Samsung-contacts meaning, the risk is mainly privacy (the backup holds personal contacts) - keep it private. Beware generic "open any SPB" converter sites, which are often adware and won't handle either real format.
Format details
in a nutshell- Samsung Kies Phone Contacts Library - Samsung Kies exports phone contacts as a .spb backup; open/convert it to VCF/CSV via Kies (see conversions note).
- Sprint Backup / other niche backups - A few backup utilities reuse .spb for proprietary backup containers unrelated to flight simulation.
Programs that open SPB files
Windows3 apps
Microsoft Flight Simulator X / Microsoft Flight Simulator
Paid The simulator loads .spb missions itself; you don't open them manually. Place add-on missions where the sim expects them.
spb2xml (SimProp Binary decompiler)
Free Run spb2xml on the .spb to decompile it into readable XML for inspection/editing.
Microsoft Flight Simulator SDK (Dev Mode)
Free In modern MSFS, use the SDK / Project Editor to work with SimProp .spb files in Dev Mode. Technical details
deep spec| Format type | Compiled binary mission/scenario file (SimProp Binary) |
| Developer | Microsoft (ESP platform / Flight Simulator SDK) |
| Source format | SimProp XML - the human-readable source document compiled into the .spb binary |
| Compilation tool | Microsoft ESP / Flight Simulator SDK Dev Mode Project Editor |
| Decompiler | spb2xml - converts .spb back to its original XML source for inspection and editing |
| Magic bytes | No published constant signature; proprietary binary layout with no documented fixed header |
| MIME type | application/octet-stream |
| Platform | Windows (Microsoft Flight Simulator ecosystem) |
| Encoding | Proprietary binary encoding of SimProp property tree data |
| Related extensions | .xml (source), .flt (saved flight), .spba (SimProp Binary Archive), .fsx (FSX project) |
| Compatible simulators | Microsoft Flight Simulator X (FSX), Microsoft ESP, Microsoft Flight Simulator 2020, Microsoft Flight Simulator 2024 |
| Typical file role | Stores scenario/mission properties - object placements, camera positions, weather settings and trigger logic |
| Editing workflow | Author in XML - compile to .spb with SDK tools; decompile with spb2xml to modify |
| Format openness | Closed/proprietary - no published format specification; binary structure reverse-engineered by community |
| Released | Microsoft ESP / Flight Simulator X (2006); also Microsoft Flight Simulator 2020/2024 |
| Specification | docs.flightsimulator.com |
SPB conversions
Community Q&A
asked by usersNo questions yet - be the first to ask about SPB files.
