This document gives you detailed instructions and information about installing Flycheck.


Flycheck needs GNU Emacs 24.3 and works best on Unix-like systems like Linux or OS X. It does not support older releases of GNU Emacs or other flavours of Emacs (e.g. XEmacs, Aquamacs, etc.).

Windows support

Flycheck does not explicitly support Windows, but tries to maintain Windows compatibility and should generally work fine on Windows, too. However, we can neither answer questions about Windows nor fix bugs that only occur on Windows without the help of active Windows users. Please watch out for known Windows issues.

Syntax checking tools

Flycheck does not check buffers itself but relies on external programs to check buffers. These programs must be installed separately. Please take a look at the list of supported languages to find out what tools are required for a particular language.

Many of these programs are available in the package repositories of Linux distributions or in Homebrew for OS X. Others can be installed with standard package managers such as Rubygems, NPM, Cabal, etc.

Package installation

We recommend to install Flycheck with Emacs’ built-in package manager. Flycheck is available in the popular MELPA archive which provides up to date snapshots of Flycheck’s development state. The sibling repository MELPA Stable serves tagged releases of Flycheck instead. We advise to use MELPA if you are fine with weekly or even daily updates. If you would prefer longer time between releases use MELPA Stable instead.

Unfortunately neither of these repositories are available in Emacs by default. You must explicitly add them to package-archives, by adding the following to your init file:

(require 'package)
(add-to-list 'package-archives
              '("melpa" . "") t)

This adds MELPA; for MELPA Stable replace with If you do not know where your init file is inspect the value of user-init-file with C-h v user-init-file.

Once the repository is set up you can install Flycheck from Emacs’ package menu at M-x list-packages, or directly with M-x package-install RET flycheck.


You may want to take a look at use-package which provides simple syntax to declare and configure packages in your init file. In addition to the Github README the article My Emacs configuration with use-package has more information about use-package. Specifically it allows to automatically install missing packages from package archive when Emacs starts.

Add the following form to your init file to setup Flycheck with use-package:

(use-package flycheck
  :ensure t
  :init (global-flycheck-mode))

Then press C-M-x with point somewhere in this form to install and enable Flycheck for the current Emacs session.

Alternative installation methods

Some users prefer to install Flycheck via other methods such as el-get, Git submodules, etc.

We do not support any of these methods, and advise against any alternative installation method. We do not consider it a bug if Flycheck works when installed as above but not with a different installation method.


If you install Flycheck in any way other than our official packages you do so at your own risk.

Please beware of breakage and understand that while we do not actively work against alternative installation methods we will not make compromises to support alternative installation methods. We will close issues reported for alternative installation if we fail to reproduce them with a proper installation of Flycheck.