LCP Before & After: A Real-World Case Study Breakdown
Reading about LCP optimization techniques is useful, but seeing how they stack together on a real page makes the impact concrete. This walkthrough illustrates a typical optimization journey for a business homepage, showing what changed and roughly how much each step contributed.
Key takeaways:
- Combining multiple smaller fixes often produces a bigger result than any single change
- Image optimization typically delivers the largest single improvement
- Server and hosting improvements set the baseline every other fix builds on
- Diminishing returns set in after the biggest issues are resolved
- Measuring after each change helps identify what actually worked
Starting Point
The example site began with a homepage LCP of roughly 5.8 seconds on mobile — well into "Poor" territory — driven by a large uncompressed hero image, a slow shared-hosting server, and several third-party marketing scripts loading before the main content.
Step-by-Step Impact
| Step | Change Made | Resulting LCP (Approximate) |
|---|---|---|
| Baseline | No changes yet | 5.8 seconds |
| 1. Image optimization | Compressed and resized hero image, converted to WebP | 3.9 seconds |
| 2. Hosting upgrade | Moved from shared hosting to a faster managed host | 3.1 seconds |
| 3. CDN added | Static assets served from edge locations | 2.7 seconds |
| 4. Deferred third-party scripts | Chat widget and marketing pixel loaded after main content | 2.3 seconds |
| 5. Preloaded hero image | Added <link rel="preload"> for the LCP image | 2.1 seconds |
By the end of this process, the page moved from "Poor" to solidly "Good" — a reduction of roughly 64% from the original score.
What Made the Biggest Difference
Image optimization alone accounted for close to a third of the total improvement, reinforcing that it's usually the first place to look. Hosting and CDN changes addressed the underlying delivery speed that every other fix depended on. The remaining steps — deferring scripts and preloading — delivered smaller, but still meaningful, refinements on top of that foundation.
Lessons From This Kind of Optimization Journey
- Start with the biggest, most obvious issue rather than trying to fix everything at once.
- Measure after each individual change, not just at the end, to understand what's actually working.
- Expect diminishing returns — the first few fixes usually deliver the largest gains, with later steps offering smaller but still worthwhile improvements.
- Revisit periodically, since new content, plugins, or scripts can erode these gains over time.
Frequently Asked Questions
Is this improvement typical for most sites?
Results vary significantly depending on a site's starting condition, but sites with an unoptimized hero image and basic shared hosting often see substantial gains from just the first two or three steps.
How long does a project like this typically take?
Image and script-level fixes can often be completed within days; hosting migrations and CDN setup may take longer depending on complexity and testing requirements.
Do these fixes need to happen in this exact order?
Not strictly, but addressing the highest-impact items first — usually images and hosting — tends to be the most efficient use of time and effort.
Next Steps for Your Business
Compare your current LCP score against the baseline in this example. If you're starting from a similarly slow point, image optimization and hosting are almost always the right first moves.
Our team can run a similar step-by-step optimization process on your site, measuring results at each stage so you know exactly what's working.