What is the FXP file format?
An .fxp file is the compiled bytecode output produced by Microsoft Visual FoxPro when a .prg source program is run or explicitly compiled. Rather than being a standalone executable, it contains proprietary p-code interpreted by the VFP runtime - VFP9R.DLL for the redistributable runtime or VFP9T.DLL for the IDE - meaning the operating system cannot run it directly.
The VFP compiler generates .fxp automatically alongside .prg files and regenerates it transparently if the .prg is newer. Deleting the .fxp forces recompilation from source. Compilation is strictly one-way: .fxp files cannot be decompiled back to readable .prg source code.
Visual FoxPro traces its roots to FoxBASE+ (1984), became a Microsoft product after the 1992 Fox Software acquisition, and reached its final release with Visual FoxPro 9.0 SP2 in 2007. Microsoft ended extended support on January 13, 2015. Despite this, a large legacy install base of line-of-business applications built in the 1990s and 2000s persists, and the free VFP9 runtime redistributable still installs on Windows 11 as of 2026, though it receives no security updates.
Bytecode is version-specific: code compiled under VFP 6 is incompatible with the VFP 9 runtime. The .prg source file is always more valuable than the compiled output. A FoxPro application typically operates alongside .DBF database tables and related artifacts such as .dbc containers and .vcx class libraries.
Security & safety
RISK: MEDIUMFXP files execute code within the VFP runtime - running an unknown FXP file could execute malicious FoxPro commands. The risk is limited by the rarity of VFP environments in 2026. FXP from the VST/audio context is harmless preset data.
Format details
in a nutshell- VST/AU Plugin Preset File (Steinberg FXP) - Steinberg's FXP format stores a single preset (patch) for a VST or AU audio plugin; companion to .FXB (full preset bank). Used by Cubase, Ableton, FL Studio, and any VST2-compatible host. Entirely unrelated to FoxPro.
Programs that open FXP files
Windows3 apps
Visual FoxPro 9.0
Paid Open the companion .PRG file in VFP IDE; .FXP is compiled automatically. Or use DO <filename>.fxp in the Command Window to execute. Note: VFP 9.0 is EOL (Jan 2015), no longer sold by Microsoft.
VFP 9.0 Runtime (redistributable)
Free Deploy the VFP9 runtime to run compiled VFP applications without the full IDE. Runtime is free; still available from Microsoft Download Center as of 2026.
Visual FoxPro Community (vfpx.codeplex.com archived)
Open-source Community-maintained tools for VFP development; does not replace the core VFP IDE but adds utilities. Technical details
deep spec| Encoding | Binary proprietary p-code (bytecode), not human-readable |
| Byte order | Little-endian |
| Container | Proprietary VFP compiled bytecode format; no standard container wrapper |
| Typical file size | 5 KB - 2 MB depending on program complexity |
| Execution model | P-code interpreted by the VFP runtime (VFP9R.DLL / VFP9T.DLL); not directly OS-executable |
| Cross-version compatibility | Bytecode is version-specific; VFP 3.0 through VFP 9.0 outputs are mutually incompatible |
| Source dependency | Auto-generated from a .prg source file; runtime recompiles automatically if .prg timestamp is newer |
| Reversibility | One-way compilation; .fxp cannot be decompiled to readable .prg source |
| Source obfuscation | Bytecode is unencrypted; source logic is nonetheless unreadable without the original .prg |
| Associated OS | Windows (VFP9 runtime installs on Windows 11 as of 2026) |
| Related project files | Typically used alongside .dbf tables, .dbc containers, .vcx class libraries, .scx forms |
| Support status | Microsoft ended extended support in January 2015; runtime receives no security patches |
| Released | 1984 (FoxBASE+); VFP-specific compiled format from Visual FoxPro 3.0, 1995 |
| Latest version | Visual FoxPro 9.0 SP2 (2007) - final version, EOL January 13, 2015 |
FXP conversions
Community Q&A
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