Jinx is a fast just-in-time spell-checker for Emacs. Jinx highlights misspelled words in the text of the visible portion of the buffer. For efficiency, Jinx highlights misspellings lazily, recognizes window boundaries and text folding, if any. For example, when unfolding or scrolling, only the newly visible part of the text is checked if it has not been checked before. Each misspelling can be corrected from a list of dictionary words presented as a completion menu.

Installing Jinx is straight-forward and configuring should not need much intervention. Jinx can be used completely on its own, but can also safely co-exist with Emacs’s built-in spell-checker Ispell.

Jinx’s high performance and low resource usage comes from directly calling the widely-used API of the Enchant library (see libenchant). Jinx automatically compiles jinx-mod.c and loads the dynamic module at startup. By binding directly to the native Enchant API, Jinx avoids the slower backend process communication with Aspell. Enchant is widely used by other text editors and supports Nuspell, Hunspell, Aspell and a few language-specific backends.

Jinx supports spell-checking multiple languages in the same buffer. See the jinx-languages variable to customize for multiple languages. Jinx can flexibly ignore misspellings via faces (jinx-exclude-faces and jinx-include-faces), regular expressions (jinx-exclude-regexps), and programmable predicates. Jinx comes preconfigured for the most important Emacs major modes. Modes like Java, Ruby or Rust are listed in jinx-camel-modes. For these modes composite words in camelCase and PascalCase are accepted.

Jinx can be installed from GNU ELPA and MELPA directly or with package-install.

Jinx requires libenchant. Enchant library is a required dependency for Jinx to compile its module at install time. If pkg-config is available when installing Jinx, Jinx will use pkg-config to locate libenchant.

On Debian or Ubuntu, install the packages libenchant-2-dev and pkg-config. On Fedora or RHEL, install the package enchant2-devel. On Mac, install enchant2 and pkgconfig.

Jinx has two modes: the command, global-jinx-mode activates globally; and the command, jinx-mode, for activating for specific modes.

;; Alternative 1: Enable Jinx globally
(add-hook 'emacs-startup-hook #'global-jinx-mode)

;; Alternative 2: Enable Jinx per mode
(dolist (hook '(text-mode-hook prog-mode-hook conf-mode-hook))
  (add-hook hook #'jinx-mode))

The commands jinx-correct and jinx-languages are autoloaded. Invoking jinx-correct corrects the misspellings. Binding jinx-correct to M-$ chord takes over that key from the default assignment to ispell-word. Since Jinx is independent of the Ispell package, M-$ can be re-used.

(keymap-global-set "<remap> <ispell-word>" #'jinx-correct)

• M-$ triggers correction for the misspelled word before point.
• C-u M-$ triggers correction for the entire buffer.

A sample configuration with the popular use-package macro is shown here:

(use-package jinx
  :hook (emacs-startup . global-jinx-mode)
  :bind ([remap ispell-word] . jinx-correct))

After invoking the command jinx-correct, suggested corrections are displayed as a completion menu. You can press digit keys to quickly select a suggestion. Furthermore the menu offers options to save the word temporarily for the current session, in the personal dictionary or in the file-local variables. Note that you can enter arbitrary input at the correction prompt in order to make the correction. The keys M-n (M-p) are bound to jinx-next and jinx-previous and allow you to move the next (previous) misspelling.

The completion menu is compatible with all popular completion UIs: Vertico, Mct, Icomplete, Ivy, Helm and of course default completion. In case you use Vertico I suggest that you tweak the completion display via vertico-multiform-mode for the completion category jinx. You can for example use the grid display such that more suggestions fit on the screen.

(add-to-list 'vertico-multiform-categories
             '(jinx grid (vertico-grid-annotate . 25)))
(vertico-multiform-mode 1)

Enchant uses different backends for different languages. The backends are ordered as specified in the personal configuration file ~/.config/enchant/enchant.ordering and the system-wide configuration file /usr/share/enchant-2/enchant.ordering. Enchant uses Hunspell as default backend for most languages. There are a few exceptions. For English Enchant prefers Aspell and for Finnish and Turkish special backends called Voikko and Zemberek are used. On non-Linux operating systems Enchant may also integrate with the spell-checker provided by the operating system.

Depending on the backend the personal dictionary will be taken from different locations, e.g., ~/.aspell.LANG.pws or ~/.config/enchant/LANG.dic. It is possible to symlink different personal dictionaries such that they are shared by different spell checkers. See the Enchant manual for details.

There exist multiple alternative spell-checking packages for Emacs, most famously the builtin ispell.el and flyspell.el packages. The main advantages of Jinx are its automatic checking of the visible text, its sharp focus on performance and the ability to easily use multiple dictionaries at once. The following three alternative packages come closest to the behavior of Jinx.

• jit-spell: Jinx UI borrows ideas from Augusto Stoffel’s Jit-spell. Jit-spell uses the less efficient Ispell process communication instead Jinx’s calling native API. Since Jit-spell highlights misspellings in the entire buffer and does not confine to just the visible text, Jit-spell affected load and latency negatively in my tests (issue on Github).
• spell-fu: The idea to check words just in the visible text came from Campbell Barton’s spell-fu package. Spell-fu is fast but incurs high memory overhead on account of its dictionary in a hash table. For languages with compound words and inflected word forms, this overhead magnifies (issue on Codeberg). By accessing the Enchant API directly, Jinx avoids any overhead. Jinx also benefits from the advanced spell-checker algorithms of Enchant (affixation, compound words, etc.).
• flyspell: Flyspell is a built-in package. Flyspell highlights misspellings while typing. Only the word under the cursor is spell-checked. Jinx, on the other hand, is more effective because it automatically checks for misspellings in the entire visible text of the buffer at once. Flyspell can check the entire buffer but must be instructed to do so via the command flyspell-buffer.

Since this package is part of GNU ELPA contributions require a copyright assignment to the FSF.