Definition

Minification is the process of removing characters from source code — including comments, whitespace and redundant declarations — that are not needed for the browser to run it. It reduces the size of HTML, CSS and JavaScript files without changing how they behave.

Minification typically strips developer comments, collapses whitespace such as tabs and spaces, and consolidates redundant code into more compact forms. It is usually automated as part of a build process, often by a bundler, so that developers keep readable source code while production assets are smaller. Minification is separate from, and complementary to, server compression such as gzip or Brotli — applying both yields a cumulative reduction in transferred bytes. Source maps are commonly generated alongside minified files to support debugging.

Examples

• Build pipeline

  A bundler minifies a site's JavaScript before deployment, reducing a 516-character snippet to around 204 characters by removing comments and whitespace.

• Combined with compression

  A team minifies its CSS and also enables Brotli on the server, so the file is both smaller and compressed in transit.

Sources

• web.dev — Reduce network payloads using text compression
• Chrome for Developers — Lighthouse overview

Related terms

• Page Speed
  How quickly a web page loads and becomes interactive, measured by metrics such as Largest Contentful Paint, Interaction to Next Paint, and Time to First Byte.
• Render-Blocking Resources
  Resources — typically CSS and synchronous JavaScript — the browser must fetch and parse before it can paint the first frame of a page.
• Core Web Vitals
  A set of three Google metrics that measure real-world page experience: loading speed, interactivity and visual stability.
• Lighthouse
  An open-source automated tool from Google that audits a web page for performance, accessibility, SEO and other best practices.
• Largest Contentful Paint
  A Core Web Vitals metric measuring how long the largest visible content element on a page takes to render after loading begins.
• Time to First Byte
  A performance metric measuring the time between a request for a page and the first byte of the response arriving back at the browser.

Where QueryCatch uses this

• Page Optimisation
• SEO Audit