How to Improve Your Website's Lighthouse Score

Lighthouse is Google's open-source audit that scores a page from 0–100 across performance, accessibility, best practices, and SEO. A higher score means a faster, more usable, more discoverable page — and Core Web Vitals are a confirmed ranking signal. Here's how to improve each area, in priority order.

Start with Core Web Vitals

Three metrics dominate the performance score:

1. Largest Contentful Paint (LCP) — how long until the largest element (usually the hero image or headline) renders. Aim for under 2.5 seconds.
2. Cumulative Layout Shift (CLS) — how much the layout jumps as it loads. Aim for under 0.1.
3. Interaction to Next Paint (INP) — how quickly the page responds to input. Aim for under 200 ms.

Fix these and the performance score usually follows.

Performance fixes that move the needle

In rough order of impact:

• Optimize the LCP image. Serve it in a modern format (WebP/AVIF), size it correctly, and preload it. An oversized hero image is the single most common LCP killer.
• Reserve space for images and embeds. Always set width and height (or an aspect ratio) so content doesn't shift — this directly fixes CLS.
• Reduce render-blocking resources. Defer non-critical JavaScript and inline only the CSS needed for the first viewport.
• Cut unused JavaScript. Ship less to the browser; code-split large bundles so each page loads only what it needs.
• Cache and compress. Enable text compression and long-lived caching for static assets.

Accessibility fixes

Accessibility is often the lowest score and the easiest to raise, because failures are specific:

• Color contrast. Ensure text meets at least a 4.5:1 contrast ratio against its background.
• Image alt text. Every meaningful image needs a descriptive alt attribute.
• Button and link names. Icon-only buttons need an aria-label; links need discernible text.
• Form labels. Every input needs an associated label.

These also improve the real experience for assistive-technology users — not just the score.

SEO fixes

The Lighthouse SEO audit is a floor, not a ceiling, but it catches basics:

• A unique, descriptive <title> and meta description.
• A single, clear <h1> and a logical heading order.
• Crawlable links and a valid robots.txt.
• Structured data where relevant.

For the deeper, content-level layer beyond Lighthouse, see AEO vs GEO vs SEO.

Don't chase 100 blindly

A perfect 100 on a synthetic test isn't the goal — a fast, usable page for real visitors is. Fix the issues that affect real users first (LCP, CLS, contrast), then polish. Lighthouse also varies run to run, so test a few times and look at the trend.

Measure your starting point

You can't improve what you don't measure. Run a free audit to get your current Lighthouse-based performance, accessibility, and SEO scores in one report, with the specific failing checks ranked by impact — or start with a focused SEO audit.