There is one other file type using
the FSI file extension!

fsi file icon.fsi - FileSplit file

Detailed description

Software that works with fsi file extension

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FSI file extension - Microsoft Visual F# Signature file

What is fsi file? How to open fsi files?

File type specification:

Source code and script file type icon Source code and script file type

fsi file icon: fsi filetype icon

The FSI file extension is associated with Microsoft Visual F#. F# is a functional programming language for the .NET Framework. It combines the succinct, expressive, and compositional style of functional programming with the runtime, libraries, interoperability, and object model of .NET.

The .fsi files are used for signature files used by Visual F#, a component of Microsoft's Visual Studio software development kit. The .fsi signature files contain information about the F# program element's public signatures, including types, namespaces, and other components.

The .fsi files can be used to specify accessibility rules to program code within an .fs file. This technique is used to restrict access to other program code that executes outside of the controlled .fs file.

The .fsi files always have the same filename as their associated .fs file.

The default software associated to fsi file type:

Microsoft Visual Studio icon

Microsoft Corporation logo Microsoft Visual Studio  Microsoft Windows software

Company or developer:
  Microsoft Corporation

Microsoft Visual Studio is an integrated development environment (IDE) used to create applications for Microsoft Windows, Windows Mobile, .NET Framework, Silverlight as well as dynamic websites and web applications.

Help how to open FSI files:

Use any of the Microsoft Visual Studio suites to work with .fsi files.

How to convert file with extension FSI:

Currently there is no specific information available, about how to convert this file extension.

For general information try to look at:
Basic info how to convert source code or script files

Related links:

F# Programming language

About F Sharp on Wikipedia

List of software applications associated to the .fsi file extension

Recommended software programs are sorted by OS platform (Windows, Mac OS X etc.) and possible program actions
that can be done with the file
: like open fsi file, edit fsi file, convert fsi file, view fsi file, play fsi file etc. (if exist software for corresponding action in's database).

Click on the tab below to simply browse between the application actions, to quickly get a list of recommended software, which is able to perform the specified software action, such as opening, editing or converting of the fsi files.

  • Open fsi file
  • Save fsi file
  • Edit fsi file
  • View fsi file
  • Create fsi file
  • Print fsi file
  • Others fsi file

Software that open fsi file - Microsoft Visual F# Signature file

Click on the link to get more information about listed programs for open fsi file action.

Microsoft Windows:

Main software associated with fsi file by default:
Microsoft Visual Studio small icon Microsoft Visual Studio
Other suggested software:
Microsoft Windows NotePad small icon Microsoft Windows NotePad
NotePad++ text editor small icon NotePad++ text editor
Nvu small icon Nvu

Apple macOS / Mac OS X:


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