To publish your images or photos to online forums such as 4chan, Reddit, webhostingtalk, photography talk, or send them as email attachments, or share them with your friends on VK, Tumblr, you may need to reduce the image size of them first. It supports the following image formats: PNG, JPG, JPEG, GIF and BMP. Online Image Resizer is a free image resizer to reduce image size online without losing quality for free. When you want to upload your images to a certain site, it may require you to resize your images to smaller sizes, the reason is that larger images will take more time to load, they will occupy more bandwidth and server resource.