Large image files slow down websites, eat up storage space, and make email attachments a pain to send. The frustrating part is that most of that file size is unnecessary. A photo straight from your phone or camera often contains far more data than any screen actually needs to display it. Compressing the image removes that excess without making any visible difference to how it looks.

What actually happens when you compress an image

Image compression works by finding and removing redundant data in the file. There are two main types. Lossless compression removes technical overhead and duplicate data without touching any pixel information, so the image looks identical before and after. Lossy compression takes things further by slightly simplifying areas of the image that the human eye is unlikely to notice, like a patch of sky that is almost the same color throughout. The result is a much smaller file that still looks great to most people.

For most everyday uses like websites, social media, and email, a small amount of lossy compression is completely fine and gives you the biggest reduction in file size.

How to compress your images using OnlineToolsPlus

1. Open the Image Compressor tool.
2. Upload your JPG or PNG file by clicking the upload area or dragging the file onto it.
3. Adjust the quality slider to your preference. For web images, somewhere between 70 and 85 usually gives the best balance of size and sharpness.
4. Click Compress and download your optimized image.

You can see the before and after file sizes right in the tool so you know exactly how much space you saved before downloading.

How much can you actually reduce the file size

It depends on the original image, but reductions of 60 to 80 percent are common for photos taken on modern smartphones. A 4 MB photo can often be brought down to under 500 KB without any visible difference when viewed on a screen. PNG files with lots of solid colors can sometimes be compressed even further.

When should you use JPG versus PNG

JPG is the better format for photographs and images with lots of colors and gradients. It compresses very efficiently and the results look great for natural images. PNG is better for screenshots, logos, graphics with text, and anything where you need sharp edges or a transparent background. PNG uses lossless compression, so it will never introduce blurriness around text or lines, but the file sizes tend to be larger than JPG for the same image.

Does compression affect image dimensions

No. Compression only affects file size, not the width and height of the image. If you also need to resize the image, for example to create a specific thumbnail size, you can use the Image Resizer tool separately or in combination with compression.