super-save

super-save auto-saves your buffers when certain events happen - e.g. you switch between buffers, an Emacs frame loses focus, etc. You can think of it as both something that augments and replaces the standard auto-save-mode.

This package requires Emacs 27.1+.

Rationale

I created super-save because I wanted Emacs to save files the way IntelliJ IDEA and other modern editors do — automatically, when you switch buffers or leave the editor. No manual C-x C-s, no thinking about it. I first wrote about this idea back in 2012, and super-save grew out of the buffer auto-saving functionality I had built for Emacs Prelude.

Emacs has a built-in auto-save-mode, but it solves a different problem — it's a crash-recovery mechanism that periodically writes buffer contents to temporary #file# backup files. That's useful as a safety net, but it's not the same as actually saving your files. You still have to remember to hit save, and you end up with #backup# files scattered around your filesystem.

super-save takes a simpler approach: it just saves your files (for real) when natural editing events happen — switching buffers, switching windows, losing focus, or going idle. No backup files, no recovery dance, no extra complexity. Your files are always saved, and you never have to think about it.

Installation

Available on all major package.el community maintained repos - MELPA Stable and MELPA repos.

MELPA Stable is recommended as it has the latest stable version. MELPA has a development snapshot for users who don't mind breakage but don't want to run from a git checkout.

You can install super-save using the following command:

M-x package-install [RET] super-save [RET]

or if you'd rather keep it in your dotfiles:

(unless (package-installed-p 'super-save)
  (package-refresh-contents)
  (package-install 'super-save))

If the installation doesn't work try refreshing the package list:

M-x package-refresh-contents

use-package

If you're into use-package you can use the following snippet:

(use-package super-save
  :ensure t
  :config
  (super-save-mode +1))

Emacs Prelude

super-save started its life as the extraction of a similar functionality I had originally developed for Emacs Prelude and the package is bundled with Prelude.

Usage

Add the following to your Emacs config to enable super-save:

(super-save-mode +1)

If you want to enable the additional feature of auto-saving buffers when Emacs is idle, add the following as well:

(setq super-save-auto-save-when-idle t)

By default the idle delay is 5 seconds. You can change it via super-save-idle-duration:

(setq super-save-idle-duration 10)

super-save-auto-save-when-idle can be set buffer-locally, so you can disable idle saving for specific modes (e.g., modes where before-save-hook runs expensive formatters):

(add-hook 'go-mode-hook (lambda () (setq-local super-save-auto-save-when-idle nil)))

At this point you can probably switch off the built-in auto-save-mode (unless you really care about its backups):

(setq auto-save-default nil)

Configuration

super-save will save files when certain events happen:

• Frame focus loss — controlled by super-save-when-focus-lost (enabled by default)
• Buffer/window switches — controlled by super-save-when-buffer-switched (enabled by default)
• Command triggers — configurable via super-save-triggers (empty by default, since the window-system hooks above already catch all buffer switches)
• Hook triggers — configurable via super-save-hook-triggers (empty by default)

;; disable saving on focus loss
(setq super-save-when-focus-lost nil)

;; disable saving on buffer/window switch
(setq super-save-when-buffer-switched nil)

;; add a command trigger (useful for commands that don't involve a buffer switch)
(add-to-list 'super-save-triggers 'ace-window)

;; add a hook trigger
(add-to-list 'super-save-hook-triggers 'find-file-hook)

You can turn off super-save for remote files like this:

(setq super-save-remote-files nil)

If you have very large files that are slow to save, you can set a size limit (in characters) via super-save-max-buffer-size:

(setq super-save-max-buffer-size 5000000)

Sometimes you might want to exclude specific files from super-save. You can achieve this via super-save-exclude, for example:

(setq super-save-exclude '(".gpg"))

The default predicates check that the buffer is visiting a file, is modified, is writable, hasn't been modified externally, and that its parent directory still exists. You can add your own predicates to super-save-predicates. These predicates must not take arguments and return nil when the current buffer shouldn't be saved. If a predicate doesn't know whether the buffer needs to be saved, it must return t. The following example stops super-save when the current buffer is in Markdown mode:

(add-to-list 'super-save-predicates (lambda ()
                                        (not (eq major-mode 'markdown-mode))))

When saving a file automatically, Emacs will display a message in the *Messages* buffer and in the echo area. If you want to suppress these messages, you can set super-save-silent to t.

;; Save silently
(setq super-save-silent t)

The super-save-delete-trailing-whitespace variable can be used to enable deleting trailing white spaces before saving (via Emacs' delete-trailing-whitespace).

;; Enable deleting trailing white spaces before saving
(setq super-save-delete-trailing-whitespace t)

;; Enable deleting trailing white spaces before saving (except for the current line)
(setq super-save-delete-trailing-whitespace 'except-current-line)

org-src and edit-indirect buffers

super-save can save org-src edit buffers (using org-edit-src-save) and edit-indirect buffers (using edit-indirect--commit). Both are enabled by default and can be disabled:

(setq super-save-handle-org-src nil)
(setq super-save-handle-edit-indirect nil)

Saving all buffers

By default, super-save will automatically save only the current buffer, if you want to save all open buffers you can set super-save-all-buffers to t.

Setting this to t can be interesting when you make indirect buffer edits, like when editing grep results with occur-mode and occur-edit-mode, or when running a project-wide search and replace with project-query-replace-regexp and so on. In these cases, we can indirectly edit several buffers without actually visiting or switching to these buffers. Hence, this option allows you to automatically save these buffers, even when they aren't visible in any window.

Skipping save hooks during auto-save

Some before-save-hook or after-save-hook functions are expensive (e.g., code formatters, database syncs) and you may not want them running on every auto-save. The variable super-save-in-progress is bound to t during all super-save operations, so you can use it to guard expensive hooks:

(add-hook 'before-save-hook
          (lambda ()
            (unless super-save-in-progress
              (my-expensive-formatting-function))))

Alternatives and Overlap

Emacs 26.1 introduced auto-save-visited-mode, which saves file-visiting buffers to their actual files after a configurable idle delay (auto-save-visited-interval, default 5 seconds). This overlaps directly with super-save's super-save-auto-save-when-idle feature, so there's no need to enable both. If idle saving is all you need, the built-in mode might be enough.

Where super-save goes further is event-driven saving — it saves immediately when you switch buffers, switch windows, or leave Emacs, rather than waiting for an idle timeout. It also provides a predicate system for fine-grained control (max buffer size, exclude patterns, remote file handling, external modification checks), silent saving, trailing whitespace cleanup, and special handling for org-src and edit-indirect buffers.

A common setup is to use super-save for event-driven saves and auto-save-visited-mode for idle saves:

(super-save-mode +1)
(auto-save-visited-mode +1)

License

Copyright © 2015-2026 Bozhidar Batsov and contributors.

Distributed under the GNU General Public License; type C-h C-c to view it.