- 83 of 200
- Performance & Core Web Vitals
- Asset Compression & Optimization
- Low
Short answer: minified JavaScript has its spaces, comments and long names stripped, so it's smaller to download and quicker for the browser to read. It's normally done by your build tool or platform. Check 83 warns when PageSpeed finds scripts that could be smaller.
What Crawl Audit checks
- Full report: Lighthouse's "Minify JavaScript" audit. A warning shows the possible saving.
- Free check: Crawl Audit can't check script files without PageSpeed, so this passes with "No unminified JavaScript detected."
What Google says
- Lighthouse: "Minifying JavaScript files can reduce payload sizes and script parse time."
- "Minification is the process of removing whitespace and any code that is not necessary to create a smaller but perfectly valid code file."
On devmarde.com
PageSpeed passed "Minify JavaScript" for our homepage on 3 October. Next.js minifies production builds.
Where it usually goes wrong
- A script copied into the theme by hand, from a vendor's "readable" version.
- A plugin or app that loads its development build.
- A site deployed from a development build by mistake.
On your platform
- WordPress: performance plugins can minify scripts. Test checkout, forms and menus after switching it on.
- Shopify, Wix and Squarespace: platform scripts are handled. Check scripts added through custom code or apps.
- Next.js and other build tools: production builds minify JavaScript by default.
Sources
- Chrome for Developers, Minify JavaScript, checked 3 October 2026.
See how your site does on every check.
Crawl Audit runs this check and 199 others on your domain. The full report is $7.89, one time. The free check on this site covers 25.