How to Reduce Image File Size for a Faster Website
Big images are the top reason pages load slowly. Resize, compress and convert your images to WebP — the right sizes, quality settings and a checklist.
3 min read ·
Images are usually the heaviest part of a web page, and oversized ones are the most common reason a site feels slow. To fix it, open the Image Compressor, add your images, set Max Width/Height to the largest size they're actually shown at, choose WebP (or JPEG), adjust the Quality, and download. Typical photos shrink by 70–95% with no visible difference.
Compress images for the web
- Open the Image Compressor and add your images — several at once is fine.
- Set Max Width/Height: 1920px (Full HD) for full-width hero images, 1280px (HD) for most content images, 800px (Web) for images inside text or thumbnails.
- Choose the Output Format: WebP for the smallest files, JPEG for maximum compatibility, or Keep Original Format.
- Set the Quality — around 75–85% is the sweet spot for photos.
- Click Compress Images and download them one by one or as a ZIP.
Why image size matters
- Speed: a 4 MB photo can take seconds to load on a phone; a 150 KB version appears almost instantly.
- Search rankings: Google measures how quickly the main content appears (Largest Contentful Paint), and a huge hero image is often the main culprit.
- Visitors' data: many people browse on capped mobile plans.
- Hosting: smaller files mean less bandwidth and storage.
The three biggest wins
1. Don't upload bigger than you display
A photo straight from a phone is about 4,000 pixels wide. Even large screens rarely show an image wider than 1,920 pixels, and most content images are shown at 600–1,200. Resizing to the displayed size typically removes most of the file size before any compression.
2. Compress sensibly
At 75–85% quality, JPEG and WebP photos look the same as the original to almost everyone while being several times smaller. Go lower for background images and thumbnails; keep higher for product photos where detail sells.
3. Use WebP
WebP files are typically 25–35% smaller than JPEGs of the same quality, and every modern browser supports them. Convert existing images with the Image Converter or choose WebP in the compressor.
Target sizes to aim for
| Image | Width | Target size |
|---|---|---|
| Full-width hero | 1920 px | under 200–300 KB |
| Content image | 1200 px | under 100–150 KB |
| Thumbnail / card | 400–600 px | under 30–50 KB |
| Logo / icon | as displayed | under 20 KB (SVG or PNG) |
For a hard limit — a CMS that refuses files over 200 KB — use Compress Image to KB, which hits an exact maximum.
PNG or JPEG or WebP?
- Photos: WebP or JPEG. Never PNG — a PNG photo can be ten times bigger.
- Logos, icons, screenshots with text: PNG or WebP (lossless), or SVG for logos.
- Images with transparency: PNG or WebP.
Whole site at once
For a folder of product photos or a gallery, the Bulk Converter & Resizer resizes and converts dozens of images in one go and downloads them as a ZIP — ideal before uploading to a shop or a CMS.
A quick checklist before publishing
- Resize to the displayed width (×2 for sharp retina screens if needed).
- Compress at 75–85% quality.
- Convert to WebP where your platform allows it.
- Give files descriptive names (blue-linen-sofa.webp) and add alt text — it helps accessibility and image search.
Frequently asked questions
Are my images uploaded?
No. They're compressed in your browser.
Will compressing again make them even smaller?
Recompressing an already-compressed image saves little and loses quality each time. Always start from the original.