Performance guide
How to compress PNG for web – reduce file size without losing quality
Large PNG files slow down websites, hurt Core Web Vitals scores, and cost you rankings and conversions. Compressing your PNGs before publishing is one of the highest-ROI performance improvements you can make. Here is how to do it right.
Why PNG file size matters for web performance
Image weight is the single largest contributor to slow page load times. Google's Core Web Vitals directly measure how fast your largest content element (LCP — Largest Contentful Paint) appears on screen. A heavy PNG hero image or product photo is often the culprit.
- LCP (Largest Contentful Paint) — Google's key metric for perceived load speed. Heavy images are the #1 cause of poor LCP scores.
- Mobile users. Mobile connections are slower than desktop. An uncompressed 2MB PNG that loads in 1 second on desktop might take 4–6 seconds on mobile.
- Bandwidth costs. If you serve images from your own CDN or hosting, smaller images mean lower egress costs at scale.
Lossless vs lossy compression: what is the difference?
| Type | How it works | Quality impact | Size reduction |
|---|---|---|---|
| Lossless | Removes redundant metadata and optimizes encoding without touching pixels | None — pixel-perfect | 10–30% typically |
| Lossy | Reduces color depth and merges near-identical colors to cut file size more aggressively | Minimal if done well — usually imperceptible | 40–80% possible |
For most web use cases, lossy PNG compression at a moderate quality setting is the best balance between file size and visual quality.
Step-by-step: compress PNG with PNGmaker
Open the PNG Compressor
Go to the Compress PNG tool. No signup needed. Everything runs in your browser — your files never leave your device.
Drop your PNG file
Drag and drop or click to upload your PNG. You will see the original file size and image dimensions.
Compression runs automatically
The tool compresses your PNG and shows you the size reduction. Compare the original and compressed versions side by side before downloading.
Download the compressed PNG
Save the compressed file. It keeps the same transparency and dimensions as the original — just a smaller file size.
When to convert to WebP instead
If you are optimizing images specifically for web page delivery (not for upload to platforms or sharing via email), converting PNG to WebP often delivers even better results:
- WebP files are typically 25–35% smaller than an equivalent compressed PNG.
- WebP supports transparency (alpha channel), so transparent PNGs can be converted to WebP without losing the transparent background.
- All modern browsers (Chrome, Safari, Firefox, Edge) support WebP. If you are building a web app or using Next.js, WebP is the better delivery format.
Rule of thumb: keep PNG as your master/working file. Serve WebP on the web. Use compressed PNG when the platform requires it (Amazon, Etsy, etc.) or when compatibility matters more than file size.
Try it with PNGmaker
Use the tool flow directly from this guide. The idea is simple: understand the workflow, then get to the result fast.