| Ext. | Description | Used by |
|---|
| [1] | Mathematica Package File | Mathematica |
| MATLAB M-File | MATLAB |
| Mercury Source File | Mercury |
| [2] | Source code | Objective-C |
| BDAV MPEG-2 transport stream | |
| MPEG Audio Layer 3 Uniform Resource Locator playlist | Media players |
| MPEG Audio Layer 3 Uniform Resource Locator playlist, using UTF-8 encoding | Media players |
| MPEG Audio Layer 3 Uniform Resource Locator playlist | Media players |
| MPEG-4 Part 14 audio | iTunes Store |
| DRM-encumbered MPEG-4 Part 14 media | iTunes Store (formerly) |
| See M4A | Apple iPhone ringtones |
| MPEG-4 Part 14 video, which may optionally be encumbered by FairPlay DRM | iTunes Store, Handbrake |
| M64 | | Mupen64 gameplay recording[3] | Mupen64 |
| MA | Autodesk Maya scene description format. The native format of the Maya modeling, animation, and rendering software.[4] | |
| MAT | MATLAB MAT-files. The native data format of the MATLAB numerical computation software. Stores numerical matrices, Boolean values, or strings. Also stores sparse arrays, nested structures, and more.[5] | MATLAB and Octave |
| MBOX | Unix mailbox format. Holds a collection of email messages. Native archive format of email clients such as Unix mail, Thunderbird, and many others.[6] | |
| [7] | Multimedia Container Format (predecessor of Matroska) | |
| [8] | Markdown-formatted text file | Markdown |
| MDB | MDB database file. The native format of the Microsoft Access database application. Used in conjunction with the Access relational database management system and as an exchange format.[9] | Microsoft Access |
| [10] | Master Data File, a Microsoft SQL Server file type | Microsoft SQL Server |
| Measurement Data Format, a binary file format for vector measurement data[11] | automotive industry, developed by Robert Bosch GmbH |
| Document save in high-resolution, created by MSOffice to scan documents (OCR) and turn them into a .DOC | Microsoft Office |
| Digital Geometry (Programmable CAD) file format, developed by DInsight | Digital Geometric Kernel |
| Model | 3D Design Plus or Simulink |
| Midi Session | Sound Imp. |
| [12] | MEX file (executable command) | Matlab |
| MGF | Wolfram System MGF bitmap format. Used by the Wolfram System user interface for storing raster images. MGF is an acronym for Mathematica Graphics Format.[13] | |
| [14] | Materials and Geometry Format | |
| MHT | MIME encapsulation of aggregate HTML documents | Web Browsers |
| Standard MIDI file | music synthetizers, Winamp |
| Matroska audio | |
| Matroska video | |
| Source code | Objective-C++ |
| MML | MathML mathematical markup language. Used for integrating mathematical formulas in web documents. Rendering of embedded MathML is supported by a number of browsers and browser additions.[15] | |
| Surface metrology or image analysis document | MountainsMap |
| MO | Modelica models. File format specified by the Modelica Association.[16] | |
| [17] | eBook | Mobipocket, Kindle |
| AMPL model file | AMPL |
| Modula language source | |
| Modula-2 source code file | Clarion Modula-2 |
| MOD | Tracker file format created for Ultimate Soundtracker for the Amiga | MOD (file format) |
| MOD | MOD is recording format for use in digital tapeless camcorders. | MOD and TOD |
| Module | GTK+ |
| MOE | same as Modelica Model .mo. | |
| MDL Molfile | RasMol |
| [18] [19] | Tripos Sybyl MOL2 Format | SYBYL, RasMol |
| MOPAC input file | MOPAC, RasMol |
| [20] | Animation format (Mac) | QuickTime, AutoCAD AutoFlix |
| [21] [22] | MPEG audio file | Winamp, xing |
| [23] [24] | MPEG audio stream, layer 3 | AWAVE, CoolEdit(+PlugIn), Winamp, many others |
| [25] | multimedia container format, MPEG 4 Part 14 | Winamp |
| MPEG audio stream, layer 1,2,3 | AWAVE |
| Musepack audio | |
| LDraw file (multi-part DAT file) | LDraw |
| [26] [27] | multimedia containter format, video, audio | MPEG Player, Winamp |
| see MPEG | |
| MPS | MPS linear programming system format (.mps)[28] Commonly used as input format by LP solvers. MPS is an acronym for Mathematical Programming System.[29] | |
| management saved console[30] | Microsoft; Microsoft MMC[31] |
| MSAV | Mindustry map file | Mindustry |
| [32] | Manchester Scene Description Language | |
| [33] [34] | Multiple sequence file (Pileup format) | |
| Windows Installer Package | Microsoft Windows |
| Microsoft Outlook metadata for a Microsoft Word 2000 email attachment[35] | Microsoft Outlook |
| Windows visual style file | Microsoft Windows |
| MSU | Microsoft Update Package | Microsoft Windows |
| See M2TS | |
| MX | Wolfram Language serialized package format (.mx) Wolfram Language serialized package format. Used for the distribution of Wolfram Language packages. Stores arbitrary Wolfram Language expressions in a serialized format optimized for fast loading.[36] | |
| [37] [38] | Material exchange format (RFC 4539, SMPTE 377M) | |
| a MyISAM data file in MySQL | MyISAM, MySQL |
| a MyISAM index file in MySQL | MyISAM, MySQL |
| MR | A Engine Simulator engine save file[39] | Engine Simulator | |
| Ext. | Description | Used by |
|---|
| Wolfram Mathematica Notebook (see Wolfram Language) | Mathematica |
| Binary Data | netCDF software package |
| Instructions for NC (Numerical Control) machine | CAMS |
| Name code program | namec-git/namec software package |
| NC Drill File (Excellon Format, printed circuit board hole definitions) | Most PCB layout software |
| NDK | NDK seismologic file format. Commonly used for storage and exchange of earthquake data. Stores geographical information and wave measurements for individual seismological events.[40] | |
| NDS | Nintendo DS file. Used for Homebrew and official games. | Nintendo DS Consoles and Emulators |
| [41] | Nikon RAW image format | Nikon cameras |
| NET | Pajek graph data format (.net) Pajek graph language and data format. Commonly used exchange format for graphs. The native format of the Pajek network analysis software. The format name is Slovenian for spider.[42] | Pajek network analysis software |
| Pro/Engineer neutral file format | PTC Pro/Engineer |
| NEX | NEXUS phylogenetic format (.nex, .nxs) Commonly used for storage and exchange of phylogenetic data. Can store DNA and protein sequences, taxa distances, alignment scores, and phylogenetic trees.[43] | |
| Instructions for NC machine made by TRUMPF | TRUMPF |
| NFO | iNFO for accompanying media files | Kodi, Plex |
| NIM | Nim source code file | Nim |
| NMF | Node Map File | Used by SpicyNodes |
| NOFF | 3D object file format with normals (.noff, .cnoff) NOFF is an acronym derived from Object File Format. Occasionally called CNOFF if color information is present.[44] | |
| Nuendo Project File | Steinberg Nuendo |
| NRO | Nintendo Switch executable file | |
| [45] | Nikon Coolpix RAW image | Nikon |
| NRX | NetRexx Script File | NetRexx |
| NetStumbler file | NetStumbler |
| media | Nullsoft Streaming Audio |
| NSF | NES sound format file | Transfer of NES music data[46] |
| media | Nullsoft Streaming Video |
| Numbers spreadsheet file | Numbers |
| NWD, NWF | Navisworks 3D drawing | Navisworks |
| NXS | Same as NEXUS (.nex, .nxs). See NEX above for more details. NEXUS phylogenetic format (.nex, .nxs) | | |
| Ext. | Description | Used by |
|---|
| Object file | UNIX - Atari - GCC |
| Compiled machine language code | |
| Object code | Intel Relocatable Object Module |
| Wavefront Object | |
| Script | ObjectScript |
| OLE custom control | |
| ODB | Database front end document | OpenDocument, LibreOffice |
| ODF[47] | Formula, mathematical equations | OpenDocument, LibreOffice |
| ODG | Drawings and vector graphics | OpenDocument, LibreOffice, Collabora Online |
| ODP | Presentations | OpenDocument, LibreOffice, Collabora Online |
| ODS | OpenDocument spreadsheet format (.ods) | OpenDocument, LibreOffice, Collabora Online |
| ODT | Text (Word processing) documents | OpenDocument, LibreOffice, Collabora Online |
| OFF | 3D object file format (.off, .coff) OFF is an acronym for Object File Format. Used for storing and exchanging 3D models.[48] | |
| OGA | Audio file in the Ogg container format | libogg |
| OGG | Vorbis audio in the Ogg container format | libogg |
| OGV | Video file in the Ogg container format | libogg |
| OGX | Ogg Multiplex Profile | libogg |
| Ogg/Opus audio file | mpv, mplayer, many others (official file format). |
| Emacs Org mode | Emacs Org mode major mode |
| Older Origin Project | Origin versions 4 or earlier |
| OpenStreetMap Changeset | OpenStreetMap |
| OSK | Osu! Skin | Osu! |
| OpenStreetMap data | OpenStreetMap |
| OpenStreetMap note | OpenStreetMap |
| Offline Storage Table | Microsoft e-mail software: Outlook Express, Microsoft Outlook |
| OSZ | Osu! Beatmap | Osu! |
| Over-the-air bitmap graphics | |
| OpenType font | |
| The Vim Outliner | A vim plugin |
| OTF | Formula, mathematical equations template | OpenDocument, LibreOffice, Collabora Online |
| OTG | Drawings and vector graphics template | OpenDocument, LibreOffice, Collabora Online |
| OTP | Presentations template | OpenDocument, LibreOffice, Collabora Online |
| OTS | Spreadsheets template | OpenDocument, LibreOffice, Collabora Online |
| OTT | Text (Word processing) documents template | OpenDocument, LibreOffice, Collabora Online |
| Overlay file (part of program to be loaded when needed) | TomTom Point of Interest |
| [49] [50] | Web ontology language (OWL) file | Protégé and other ontology editors |
| OpenOffice.org extension | OpenOffice.org / LibreOffice | |
| Ext. | Description | Used by |
|---|
| Database PROGRESS source code | PROGRESS |
| PASCAL source code file | |
| Parser source code file | |
| PICO-8 Game File | PICO-8 |
| Certificate Request | |
| Personal Information Exchange | "Crypto Shell Extensions" |
| [51] | Pack200 Packed Jar File | |
| Pages document file | Pages |
| Archive | Pak |
| Paint Shop Pro color palette (JASC format) | PaintShop Pro, XnView |
| PAM Portable Arbitrary Map graphics format | Netpbm |
| PAPA | Flipline Studio's game backups like JackSmith, Papa's Wingeria verion 1.2+, Papa's Pancakeria version 1.4+[52] | |
| Parity Archive | [53] |
| Parity Archive v2 | [54] |
| PARAMS | MXNet net representation format (.json, .params) Underlying format of the MXNet deep learning framework, used by the Wolfram Language. Networks saved as MXNet are stored as two separate file: a .json file specifying the network topology and a .params file specifying the numeric arrays used in the network.[55] | |
| Pascal language source | Borland Pascal |
| pax archive file | pax, GNU Tar |
| Power Library | PowerBASIC |
| PBM | ASCII portable bitmap format (.pbm) PBM monochrome raster image format. Member of the Portable family of image formats. Related to PGM and PPM. Native format of the Netpbm graphics software package.[56] | Netpbm graphics software package |
| PBO | A file type used by Bohemia Interactive | Arma 3, PBO Manager |
| PCAP | Network packet capture format (.pcap)[57] | WireShark[58] |
| [59] [60] | HP-PCL graphics data file | HP Printer Command Language |
| PCSurvey file | PCSurvey by Softart - Land Surveying Software |
| PC Paintbrush file | PC Paintbrush |
| [61] | debugging data | Microsoft Windows |
| [62] | Molecule (protein data bank) | |
| Processing source code file | Processing programming language |
| Adobe's Portable Document Format | Adobe Acrobat Reader |
| Portable Database Image | |
| Program | Deskmate |
| PowerDesigner's physical data model (relational model) file format | PowerDesigner |
| Visual Basic (VB) Project Information File | Visual Basic |
| Image file | Paint.NET |
| PALASM Design Description | |
| Planetary Data System Format | |
| A text-based certificate file defined in RFC 1421 through RFC 1424[63] | Applications that need to use cryptographic certificates, including web-servers |
| package[64] | Puppy Linux |
| PostScript Font File | |
| Type 3 font file (unhinted PostScript font) | |
| PFAM format | |
| PostScript font | Adobe Type Manager (ATM) |
| (Personal Filing Cabinet) contains e-mail, preferences and other personal information | AOL |
| [65] | PostScript Type 1 font metric file | Microsoft Windows, Adobe Acrobat Reader |
| Windows Type 1 font metric file | |
| [66] | Portable Game Notation -Text specification for Chess game | Most chess playing computer applications |
| An encrypted certificate file | Applications that need to use cryptographic certificates, including web-servers |
| Database File | Nuverb Systems Inc: Donarius |
| PHN | Phun scene | Algodoo (previously Phun) |
| PHP file | |
| PHP 3 file | |
| PHP 4 file | |
| Phrases | LocoScript |
| Phylip format | |
| PHZ | Algodoo scene | Algodoo |
| Portrait Innovations High Resolution Encrypted Image file | Portrait Innovations Studio2 (proprietary) |
| GlovePIE script file | GlovePIE |
| PIR format[67] | |
| Compressed Mac file archive created by PACKIT | unpackit.zoo |
| Partition Information Table for Samsung's smartphone with Android | Odin3 |
| PK3 | Quake III engine game data | |
| Pickle file | Python object serialization |
| Archive | PKARC |
| Perl source code file | |
| Prolog source code file | |
| IRAF pixel list | IRAF astronomical data format |
| PL/I source file | PL/I compilers |
| PLR | Terraria player/character file | Terraria |
| PLS | Multimedia Playlist, primarily for streaming | Shoutcast, IceCast, others |
| [68] | Perl module | |
| PMarc Archive | |
| PenguinMod Project file | PenguinMod's project file |
| Portable Network Graphics file | Web browsers, image viewing and editing applications |
| [69] | Build manager configuration file | Apache Maven POM file |
| parsimonious PEG grammar | parsimonious parser generator |
| MS Office Open-XML Presentation | Microsoft PowerPoint[70] |
| MS Office Open-XML Auto-Play Presentation | Microsoft PowerPoint |
| Mkd (Unix command) | Mkd project file to extract documentation |
| PROPERTIES | Configuration file format. Commonly used in Java projects. Associates string keys to string values.[71] | |
| [72] | Message specification | Google Protocol Buffers |
| Plasma Registry Page | Plasma (engine) |
| Adobe Postscript file | PostScript |
| [73] | Photoshop native file format | Adobe Photoshop |
| PSDC | Photoshop Cloud Document | Adobe Photoshop |
| [74] | Windows Powershell module | Windows Powershell |
| [75] | Paint Shop Pro color palette (JASC format) | Paint Shop Pro 8.0 and newer |
| Archive File | Microsoft Outlook |
| PS1 | Windows Powershell script | Windows PowerShell |
| PlayStation Portable Theme file | PSP Theme settings menu |
| Pro Tools Session File | Digidesign/Avid Pro Tools version 7 up to version 9 |
| Pro Tools Session File | Digidesign Pro Tools (legacy version) |
| Pro Tools Session File | Avid Pro Tools version 10 or later |
| Public key ring file | Pretty Good Privacy RSA System |
| Pileup format | |
| Python script file | Python (programming language) | |
