Images are usually the heaviest part of a web page. A single photo straight from a modern phone can be 4 to 6 megabytes. Put ten of those in a blog post and the page becomes painfully slow on mobile data. The fix is simple: resize and compress every image before uploading. Most of the time nobody can see the difference, except in loading speed.
What our optimizer does
The Image Size Optimizer works fully inside your browser. Your image is never uploaded to a server. You can:
- Choose the output format: WebP for the smallest size, JPEG for compatibility or PNG for graphics with transparency
- Set the quality from 10 to 100
- Set a maximum width to resize large photos
- See before and after sizes and the percentage saved
- Preview and download the optimized file
How to use it
- Open the Image Size Optimizer.
- Choose an image from your device.
- Select WebP, set quality around 75 and a max width such as 1200 pixels.
- Click Optimize Image.
- Download the new file and upload it to your website.
Best settings for websites
- Blog and product photos: WebP, quality 70 to 80, max width 1200 to 1600 pixels
- Thumbnails: WebP, quality 70, max width 400 to 600 pixels
- Logos and icons with transparency: PNG or WebP
- Social sharing images: 1200 by 630 pixels, quality 80
Why WebP
WebP files are usually 25 to 35 percent smaller than JPEG at similar quality, and modern browsers support them widely. Many sites cut total page weight in half just by switching images to WebP.
Give images good names and alt text
Before uploading, rename the file with descriptive words, for example red-cotton-kurta-front.webp instead of IMG_20260512.jpg. Our Image Filename Generator creates clean names. Then add descriptive alt text, which you can draft with the Image Alt Text Generator.
Check the whole page
After optimizing, measure the result with the Website Page Size Checker. It shows which images are still heavy.
A real example
A home cook who sold frozen food online uploaded phone photos directly to her product pages. Each photo was over 4 MB and the shop took ages to open in WhatsApp's in app browser. She ran every photo through the optimizer with WebP at quality 75 and a width of 1200 pixels. Each file dropped to around 150 KB. The shop opened quickly even on 4G, and she noticed more orders coming from customers who previously gave up waiting.
A simple routine
Make optimizing part of your upload process. Keep the tool open in a tab, process each photo before uploading and save the optimized versions in a separate folder. Two extra minutes per post saves your visitors many seconds every time they open your pages.
Common mistakes to avoid
The most common mistake is uploading a photo straight from a phone camera. These files are often 4000 pixels wide and several megabytes in size, while your blog column may only be 800 pixels wide. Another mistake is saving logos and icons as JPG, which makes edges blurry. Use SVG or PNG for those. Some people compress the same image again and again, which slowly destroys the quality, so always keep the original file safe and compress a fresh copy. Also check your theme. Some themes load a full size image in a small thumbnail box, which wastes bandwidth on every visit.
A good target for most blog images is under 150 KB, and for large hero banners under 300 KB. Product photos for an online store can sit around 100 KB each when saved as WebP at the right width.
Frequently asked questions
Is my image uploaded anywhere
No. All processing happens in your browser.
Will the image lose quality
At quality 70 to 80 most people cannot see any difference on screen.
Can I optimize many images at once
The tool processes one image at a time for best control and privacy.
Shrink your images now with the free Image Size Optimizer.