Why Your Images Are Slowing Down Your Website (And How to Fix It)

Published on: Nov 24, 2025 by Dr. Talib

We've all been there. You build a beautiful website, it looks great on your MacBook Pro with fiber internet, but then you check the Google PageSpeed score and it's a disaster. The culprit? Usually, it's the images.

The "Developer Bias"

As developers, we often have high-end devices and fast internet. We forget that a user on a 3G connection in a subway tunnel is trying to load our 5MB hero image. Optimizing images isn't just about scores; it's about empathy for your users.

1. Format Matters (Stop Using PNGs for Photos)

Here is a simple rule of thumb:

• Photos: Use JPG or WebP.
• Logos/Icons: Use SVG or PNG.
• Animations: Use Video or WebM (GIFs are huge).

WebP is the modern standard. It offers superior compression for images on the web. If you aren't using it, you are leaving performance on the table.

2. Size vs. Resolution

If your image is displayed at 300x300 pixels on the screen, but the actual image file is 3000x3000 pixels, you are wasting bandwidth. The browser has to download the huge file and then shrink it down.

The Fix: Resize your images to the maximum width they will be displayed at.

3. Lazy Loading

This is the easiest performance win you will ever get. Lazy loading tells the browser, "Don't download this image until the user scrolls down to it."

You don't need a library anymore. Just add this attribute:

<img src="photo.jpg" loading="lazy" alt="My Photo">

That's it. Native lazy loading is supported in all modern browsers.

4. Tools of the Trade

You don't need Photoshop to optimize images. Here are free tools I use every day:

• TinyPNG: Great for compressing PNGs and JPGs without losing quality.
• Squoosh (by Google): An incredible web app that lets you visually compare compression settings and convert to WebP.