Skip to content


Repository files navigation

Visual Studio Marketplace Downloads Visual Studio Marketplace Installs GitHub Workflow Status Visual Studio Marketplace Version (including pre-releases) GitHub

Key FeaturesGet StartedLSPLintDebugFormatSnippetsDonate

Key Features

Get Started & Seek Support

Useful Tools

Language Server integration

The Fortran Language Server fortls is responsible for providing a lot of the higher level, IDE functionality. By default, Modern Fortran will attempt to use it for hover, autocompletion, symbols and Go to & Peeking into definitions.

Allow for fortls to be automatically installed with pip or Anaconda and if the location where fortls is installed is not in your PATH point VS Code to the fortls location by setting

  "fortran.fortls.path": "/custom/path/to/fortls"

For more about the Language Server's capabilities please refer to the documentation of fortls.


Linting allows for compiler error and warning detection while coding without the user having to compile.

Vendor Compiler
GNU gfortran
Intel ifort, ifx
NAG nagfor

Using an invalid if expression


Using incorrect type and rank as function argument


📝️ Note Save your file to generate linting results

Linting results can be improved by providing additional options to the compiler.

Including directories

You can control the include paths to be used by the linter with the fortran.linter.includePaths option.

❗️ Important For the best linting results linter.includePaths should match the included paths for your project's compilation.
  "fortran.linter.includePaths": ["/usr/include/**", "${workspaceFolder}/include/**"]
❗️ Important If a glob pattern is used only directories matching the pattern will be included

Additional linting options

More options can be passed to the linter via

  "fortran.linter.extraArgs": [

Default value is -Wall (or -warn all for ifort).

Changing linting compiler

By default, the linter used is gfortran, Intel's ifort and Intel's LLVM based compiler ifx are also supported. One can use a different linter compiler via the option

  "fortran.linter.compiler": "ifort" | "gfortran" | "ifx" | "Disabled"

The linter executable is assumed to be found in the PATH. In order to use a different executable or if the executable can't be found in the PATH you can point the extension to another linter with the fortran.linter.compilerPath option.

  "fortran.linter.compilerPath": "/opt/oneapi/compiler/2022.0.2/linux/bin/intel64/ifort"



The extension uses the debugger from Microsoft's C/C++ extension for Visual Studio Code. This allows this extension to use the full functionality of the C/C++ extension for debugging applications: (un)conditional breaking points, expression evaluation, multithreaded debugging, call stack, stepping, watch window.

A minimal launch.json script, responsible for controlling the debugger, is provided below. However, Visual Studio Code is also capable of autogenerating a launch.json file and the configurations inside the file.

More details about how to set up the debugger can be found in Microsoft's website:

Example: Launch.json
  // Use IntelliSense to learn about possible attributes.
  // Hover to view descriptions of existing attributes.
  // For more information, visit:
  "version": "0.2.0",
  "configurations": [
      "name": "(gdb) Fortran",
      "type": "cppdbg",
      "request": "launch",
      "program": "${workspaceFolder}/a.out",
      "args": [], // Possible input args for a.out
      "stopAtEntry": false,
      "cwd": "${workspaceFolder}",
      "environment": [],
      "externalConsole": false,
      "MIMode": "gdb",
      "setupCommands": [
          "description": "Enable pretty-printing for gdb",
          "text": "-enable-pretty-printing",
          "ignoreFailures": true,


Two formatters are supported findent and fprettify. Both of them can be installed with pip automatically through the extension.

Demo: formatters in action
findent fprettify
alt alt

The formatter is controlled by the user option

  "fortran.formatting.formatter": "findent" | "fprettify" | "Disabled"

Additional arguments to the formatter can be input using

  "fortran.formatting.findentArgs": ["-Cn", "-Rr"],
  "fortran.formatting.fprettifyArgs": ["--whitespace-comma", "--enable-decl"]

To check all available arguments to formatters try findent -h or fprettify -h in a terminal.

If the formatter is not present in the PATH its location can be input with

  "fortran.formatting.path": "./custom/path/venv/bin"
📝️ Note findent can also be used to generate dependency files for a project.

Fortran Package Manager

Validation of fpm.toml

Autocompletion and options validation for fpm.toml files are provided by the installing the Even Better TOML Visual Studio Code extension.



Snippets are included by both fortls Language Server and the Modern Fortran VS Code extension. Some available snippets can be seen below. Users can define their own snippets by following these VS Code instructions.

If you think a snippet should be shipped by with the extension feel free to submit a feature request

Demo: snippets in action

program snippet module snippet

Advanced options

To show the symbols in the file outline enable provide.symbols. Symbols can be served by the fortls, the built-in, both or none. By default fortls is used.

  "fortran.provide.symbols": "fortls" | "Built-in" | "Both" | "Disable"

You can also configure the case for fortran intrinsics auto-complete by using

    "fortran.preferredCase": "lowercase" | "uppercase"


For debugging you need to have one of the following debuggers installed:

  • Linux: GDB
  • macOS: GDB or LLDB
  • Windows: GDB or Visual Studio Windows Debugger


Support Us

You can support further development of the extension by fiscal donations:

to our LFortan project on NumFOCUS


directly sponsoring developers through GitHub Sponsors