In this guide, we’ll explore techniques and best practices to reduce unused JavaScript in your Shopify store. By optimizing your JavaScript, you can enhance performance and provide a better user experience. We’ll cover assessment methods, techniques for eliminating unused code, and tips for managing JavaScript effectively.
Once you understand your JavaScript usage, we’ll discuss techniques to reduce unused code. This includes removing unused libraries, consolidating and minifying JavaScript files, and implementing code splitting and lazy loading. These strategies will streamline your codebase, improve loading times, and enhance performance.
Implementing the techniques and best practices discussed in this guide can significantly reduce unused JavaScript in your Shopify store. The result will be a faster, more efficient website with an exceptional user experience. Now, let’s dive into the details and optimize your Shopify store’s JavaScript for optimal performance.
Table of content
- Table of content
- Understanding unused JavaScript in Shopify
- Assessing your Shopify store’s JavaScript
- Techniques to reduce unused JavaScript from Shopify
- Best practices for JavaScript management
- Handling third-party apps and JavaScript
- Conclusion
Understanding unused JavaScript in Shopify
Unused JavaScript refers to irrelevant or deferrable JS code on your website. While that code isn’t essential for user experience, the browser prioritizes it when processing the page. As a result, the crucial elements of a website (think: above-the-fold content) are on standby until the render-blocking JavaScript takes its sweet time.
Unused JavaScript can slow your page load speed, consume more bandwidth and resources, and reduce your SEO ranking and accessibility. Therefore, it is essential to understand what unused JavaScript is and how it affects your Shopify store.
There are various causes and sources of unused JavaScript in Shopify. Some of the common ones are:
- Conditional loading: This is when you load JavaScript code only needed for specific conditions or scenarios, such as device type, browser type, user interaction, etc. For example, load a script that handles a pop-up modal that only appears when a user clicks a button. However, the script is never used if the user never clicks that button.
- Browser compatibility: This is when you load JavaScript code only needed for specific browsers or versions, such as polyfills or fallbacks. For example, you might load a script that enables a feature not supported by older browsers. However, the script is never used if the user visits your site with a modern browser.
- Code errors: This is when you load JavaScript code that contains errors or bugs that prevent it from executing correctly. For example, you might load a script with a syntax error or a missing dependency. However, the script is never used if the browser encounters an error while parsing or running the script.
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Assessing your Shopify store’s JavaScript
Before you set out to minimize unused JavaScript, you must first recognize the landscape. Grasping the extent and impact of unused JavaScript on your Shopify store’s performance forms the first mile of your optimization journey. An assessment pinpoints the issues and helps monitor improvements over time.
Measurement tools: your navigation aids
Fortunately, we’re not left wandering in the dark. Several robust tools can guide us in understanding the volume of unused JavaScript:
- Google Lighthouse: This open-source, automated tool for improving the quality of web pages provides a thorough performance audit, giving specific insights about unused JavaScript, which can be a great starting point.
- Chrome DevTools: Google Chrome browser comes with an embedded set of tools specifically for web developers. Its ‘Coverage’ tab visually shows you what code has been executed and what hasn’t, giving you a clear picture of the unused JavaScript landscape.
- WebPageTest: This is a productive tool that gauges performance from various global locations using actual consumer connection speeds and real browsers. It helps highlight third-party scripts contributing to unused JavaScript.
These tools won’t just tell you that you have unused JavaScript. They can also show you a line-by-line breakdown of used and unused code in each script file.
Reading the map: interpreting the results
- Unused JavaScript is often reported in kilobytes (KB) or percentages. A high value is a red flag.
- Pay special attention to third-party scripts.
- Large files with high unused percentages should be prioritized.
An ongoing journey: continuous assessment
- Schedule regular audits.
- Reassess after installing or removing apps.
- Use performance budgets to control JavaScript growth.
Techniques to reduce unused JavaScript from Shopify
Effectively techniques to reduce unused JavaScript from Shopify store involves a blend of strategic removal, advanced loading techniques, and resource optimization.
1. Prune apps and features
Bulky apps and unneeded theme features often contribute significantly to the unused JavaScript in a Shopify store.
- App audit: Review installed apps and remove unnecessary ones.
- Theme feature audit:
- Evaluate features from your Shopify theme
- Disable unused features
- Ensure associated JavaScript is removed
2. Minification and compression
- JavaScript minification: Use tools like UglifyJS or Terser.
- Compression: Use Gzip or Brotli to reduce file size by up to 70%.
3. Deferring JavaScript loading
- Add the
deferattribute to script tags.
4. Asynchronous loading
- Add the
asyncattribute to script tags.
5. Code splitting
- Use tools like Webpack to split JavaScript into smaller chunks.
6. Lazy loading
- Use the Intersection Observer API to delay loading JavaScript.
7. Implement tree shaking
- Use Webpack or Rollup to remove dead code.
8. Adopt HTTP/2
- Enable HTTP/2 on your server.
9. Inline critical JavaScript
- Identify and inline critical JavaScript for above-the-fold content.
10. Regular review and cleanup
- Schedule regular JavaScript reviews and remove unused code.
Best practices for JavaScript management
- Organize your code
- Use modular JavaScript
- Follow consistent naming conventions
- Regularly update and maintain dependencies
- Monitor and update dependencies
- Audit dependencies for security issues
- Leverage modern JavaScript Syntax
- Use ES6 or later syntax
- Regular testing and debugging
- Write test cases
- Use debugging tools
- Document your JavaScript code
- Comment your code
- Maintain codebase documentation
Handling third-party apps and JavaScript
Managing third-party apps and their associated JavaScript is critical.
1. Evaluate third-party apps
- Audit installed apps
- Research before installing new apps
2. Limit third-party scripts
- Monitor script loading
- Request optimization from app developers
3. Regularly monitor performance
- Use performance monitoring tools
- Compare performance before and after app installation
Conclusion
In this blog, we’ve journeyed through understanding unused JavaScript, assessing its impact, and exploring numerous techniques to reduce unused JavaScript from Shopify presence.
Unused JavaScript can negatively impact a Shopify store’s performance and user experience, affecting conversions and sales.
Remember, maintaining your Shopify store is a constant process; even minor improvements in your JavaScript usage can lead to significant enhancements in performance over time. Keep striving for efficiency and a better user experience.
