Reducing Emacs Startup Flicker: Choosing Between early-init.el and init.el

The Problem: Visual Flicker and Slow Boot

When Emacs starts, it creates the GUI frame before reading your init.el. If your configuration disables the toolbar, menu bar, or scroll bar, Emacs first draws them and then removes them a few milliseconds later, causing a visible flicker. Loading heavy packages during this initial phase also delays the moment the editor becomes interactive.

Decision Guide: Where to Place Configuration

The decision hinges on whether a setting affects the creation of the initial frame or the behavior of the editor after the frame exists.

Configuration Placement Table

Feature	early-init.el	init.el
GUI elements (tool bar, menu bar, scroll bar)	Recommended (prevents flicker)	Supported (causes flicker)
Package load paths and package-user-dir	Recommended (sets base before package system)	Supported (after package-initialize)
Mode‑specific settings (hooks, mode variables)	Not supported (no buffers yet)	Recommended
Global keybindings	Limited (only before frame)	Recommended
Package installation and activation	Too early	Recommended

Trade‑offs and Constraints

early-init.el runs before the GUI frame is fully initialized, so any function that expects an active window, a selected buffer, or a defined major mode will signal an error. Over‑using deferred loading (:defer t) in init.el can create “lazy‑loading gaps” where a keybinding is unavailable until you trigger the associated mode, which may feel like a missing shortcut.

Implementation Example

Both files belong in ~/.emacs.d/. Adjust paths as needed for your system.

early-init.el – environment and UI setup

;; ~/.emacs.d/early-init.el
;; Inhibit the startup splash screen
(setq inhibit-startup-screen t)
;; Disable unnecessary UI elements before the frame appears
(menu-bar-mode -1)
(tool-bar-mode -1)
(scroll-bar-mode -1)

init.el – package management and user customizations

;; ~/.emacs.d/init.el
(require 'package)
(package-initialize)

;; Example of deferred loading to keep startup fast
(use-package magit
  :ensure t
  :defer t)

Verification and Diagnostics

Restart Emacs. The splash screen, menu bar, tool bar, and scroll bar should be absent from the very first frame, with no visible jump or flicker.

To measure startup time, run inside Emacs:

M-x benchmark-init

If benchmark-init is not available, you can invoke Emacs from a shell to check for errors:

emacs --doctor

Risk note: Moving package-initialize into early-init.el may break packages that rely on user-emacs-directory being fully set, leading to load‑path errors.

Rollback Procedure

If Emacs fails to start or shows odd GUI behavior after adding early-init.el:

1. Rename ~/.emacs.d/early-init.el to ~/.emacs.d/early-init.el.bak
2. Restart Emacs. It will ignore the backup file and use only init.el.