Optimiser le temps de démarrage

When users launch your Electron application, their first impression is critical. A slow startup can lead to frustration and a perception of a poorly optimized app.

Optimizing startup time isn't just about raw speed; it's about providing a smooth, responsive experience from the moment your app icon is clicked.

Several factors can contribute to a slow Electron startup:

• Large Bundles: A huge JavaScript bundle for the renderer process takes time to load and parse.
• Synchronous Operations: Blocking I/O or heavy computations in the main or preload process can halt startup.
• Unnecessary Modules: Loading modules or services that aren't immediately needed.
• Too Many Windows: Creating multiple BrowserWindow instances at launch.

Not everything needs to happen immediately when your app launches. You can improve perceived and actual startup speed by deferring non-essential tasks.

Use app.whenReady() for core app initialization, then use setTimeout or other async patterns to delay tasks like checking for updates, loading analytics, or complex data processing.

Try running this example:

Preload scripts run in a sandboxed environment, but they execute before your renderer process content loads. Any heavy operations here will block the main window from appearing.

• Minimize Dependencies: Only include what's absolutely necessary.
• Avoid Heavy Logic: Don't perform complex calculations or blocking I/O.
• Expose APIs Securely: Use contextBridge to expose only specific, validated functions.

For your renderer process (the web content), treat it like a web application. Use modern web development techniques to reduce the initial bundle size.

• Code Splitting: Break your JavaScript into smaller chunks that can be loaded on demand. Tools like Webpack or Rollup support this.
• Lazy Loading: Only load components or modules when they are actually needed (e.g., when a user navigates to a specific view).

Electron applications are often packaged into an ASAR (Atom Shell Archive) file. This is a simple, tar-like format that concatenates all your application's files into one.

While not a direct code optimization, ASAR archives can significantly speed up file reading, especially on Windows, by reducing the number of file system calls, thus improving startup performance.

Since the renderer process is essentially a web browser, standard web optimization techniques apply:

• Minify Code: Reduce the size of your HTML, CSS, and JavaScript files by removing unnecessary characters (whitespace, comments).
• Compress Images: Optimize image sizes and use modern formats (e.g., WebP) to reduce load times.
• Font Optimization: Load only necessary font weights and subsets.

You can create your BrowserWindow instance earlier, even setting show: false, and then load your content.

This allows Electron to prepare the window infrastructure in the background while other startup tasks complete. Showing it only when ready-to-show fires ensures a flicker-free experience.

A splash screen is a small, simple window displayed immediately at launch while your main application loads in the background.

It gives users instant visual feedback that the app is starting, making the perceived startup time feel much faster, even if the actual loading time remains the same.

Which of the following strategies can help reduce your Electron application's startup time?

We've explored several key strategies to optimize your Electron application's startup time:

• Defer & Lazy Load: Postpone non-essential work in both main and renderer processes.
• Lean Preload: Keep your preload scripts as minimal as possible.
• Optimize Assets: Minify, compress, and use ASAR archives.
• Perceived Speed: Use splash screens and early window creation for a better user experience.

Applying these techniques will make your Electron app feel snappier and more professional.