If you're still serving PNG images on your website, you're leaving performance on the table.

Google has been pushing WebP for years. It's smaller than PNG, loads faster, and directly impacts your Core Web Vitals score — which affects your SEO ranking. The switch from PNG to WebP is one of the easiest performance wins you can make.

Here's everything you need to know — and how to convert your images for free without uploading them anywhere.

What Is WebP?

WebP is a modern image format developed by Google. It supports both lossless and lossy compression, transparency (like PNG), and animation (like GIF).

The numbers speak for themselves:

• WebP lossless images are 26% smaller than PNGs
• WebP lossy images are 25-34% smaller than JPEGs at equivalent quality
• Supported by all modern browsers — Chrome, Firefox, Safari, Edge

Why PNG to WebP Matters for Performance

Every kilobyte of image data your browser has to download slows your page load. Slower pages mean:

• Higher bounce rates
• Lower Core Web Vitals scores (LCP, CLS)
• Lower Google search rankings
• Worse user experience on mobile

Switching from PNG to WebP is one of the fastest wins in web performance. You keep the same visual quality — you just deliver it in a smaller package.

How to Convert PNG to WebP for Free

ConvertifyHub converts PNG to WebP entirely in your browser. No upload, no server, no account needed. Your files never leave your device.

Step 1

Go to convertifyhub.net and open the Image Converter.

Step 2

Drop your PNG file. Batch conversion is supported — drop multiple files at once.

Step 3

Select WebP as the output format. Adjust the quality slider if needed (80-85% is the sweet spot for most web images).

Step 4

Download your WebP file and replace the PNG on your website.

Done. No upload, no account, no cost.

PNG vs WebP — Full Comparison

The Right Quality Setting

WebP quality works on a scale of 0–100. Here's a quick guide:

• 90-100% — Near lossless. Great for product images, photography where detail matters
• 80-85% — Sweet spot for most web images. Significant size reduction, no visible quality loss
• 70-75% — Good for thumbnails, background images, decorative elements
• Below 70% — Noticeable quality loss. Avoid for anything important

For most websites, 80-85% gives you the best size-to-quality ratio.

How to Use WebP on Your Website

In HTML

<picture>
  <source srcset="image.webp" type="image/webp">
  <img src="image.png" alt="Description">
</picture>

The <picture> element serves WebP to browsers that support it and falls back to PNG for older browsers.

In CSS

.hero {
  background-image: url('hero.webp');
}

In Next.js

Next.js automatically optimizes and converts images to WebP when you use the <Image> component:

import Image from 'next/image'

<Image src="/hero.png" alt="Hero" width={800} height={600} />

Next.js handles the WebP conversion at build time. You don't even need to manually convert.

In React with Vite

Vite can handle image optimization with plugins like vite-plugin-imagemin:

npm install vite-plugin-imagemin --save-dev

Other Ways to Convert PNG to WebP

Using cwebp (Command Line)

Google's official WebP encoder:

# Install
brew install webp  # macOS
sudo apt install webp  # Ubuntu

# Convert single file
cwebp -q 85 image.png -o image.webp

# Batch convert all PNGs in a folder
for f in *.png; do cwebp -q 85 "$f" -o "${f%.png}.webp"; done

Using Sharp (Node.js)

const sharp = require('sharp');

sharp('input.png')
  .webp({ quality: 85 })
  .toFile('output.webp');

Using Squoosh (Google's Tool)

Google's Squoosh is another browser-based option. Also client-side, great for single image optimization with detailed control.

Using ConvertifyHub (Easiest)

No installation, no command line, no Node.js. Just open convertifyhub.net, drop your PNGs, and download WebPs. Works on any device.

Checklist: Migrating Your Site to WebP

• [ ] Audit your current images — find the largest PNGs
• [ ] Convert them to WebP using ConvertifyHub or cwebp
• [ ] Use <picture> tags with PNG fallback for older browser support
• [ ] Update CSS background images to WebP
• [ ] Test Core Web Vitals before and after with PageSpeed Insights
• [ ] Set up automated WebP conversion in your build pipeline

Wrapping Up

PNG is great for editing and archiving. For web delivery, WebP is almost always the better choice — smaller files, faster loads, better SEO.

Converting is free and takes seconds. If you want to do it without uploading your images to a server, ConvertifyHub handles it entirely in your browser.

No upload. No account. Just convert.

👉 Try ConvertifyHub →

About the Author

Ahmer Arain — Full-stack developer specializing in MERN stack, Next.js, and AWS. Builder of ConvertifyHub and Eternally.

🌐 ahmerarain.com
💼 linkedin.com/in/ahmer-arain
🐙 github.com/ahmerarain