Image is a critical element for each website because it makes web pages nice and vivid. For some sites include multiple fascinating images, they are more likely to hold in the good graces of visitors as long as all the images are optimized properly and set on the right place. In addition, optimizing websites images is also a valid way to speed up page loading speed.

Some webmasters are always baffled about how to resize an image in good quality. To this end, there are various optimization tools available for users to optimize and shrink the images. Here, we recommend five the most user-friendly online image optimization tools that you will need.

Kraken.io

The purpose of Kraken.io is to help users optimize images and speed their websites. It performs well on image compression and promises to compress the size of an image as tiny as possible without sacrificing the quality. As the picture we display below, it has been compressed by 74% from 907kb down to 236kb. The left is the original image and the other half is Kraken image. Frankly, we cannot tell any difference from them.

And now, this robust tool has optimized over 35 million images worldwide and also cooperated with WordPress Image Optimization plugin to make image optimization easier. On the easy-to-use web interface, you can upload or drop your image on the interface and choose the optimization mode of lossy or lossless. Note that, if you determine to sacrifice the image quality a little bit but save up to 90% file weight, you can choose the lossy optimization option.

Smush.it

Smush.it is one of the most popular image optimization tools released by Yahoo, designed to edit images and reduce the file size. As a lossless tool, it retains the visual quality of all the optimized images with high definition. With advanced techniques specific to image optimization, it helps users to cut the dimension of an image and reduce the file size as much as possible. Once running on a web page, this tool can work out that how many bytes are saved after optimizing the images on this page as well as compress the files in the minimal size.

Webresizer

Webresizer is a free online photo resizing tool targeted for making photo faster without the need for downloading any complex software. Users can upload an image up to 10MB and resize it online at any time. Besides, it supports JPG, GIF and PNG to meet the maximum satisfaction of people.

For there is no registration required, people can start optimizing images once accessing to this online tool. On the intuitive interface, you are able to adjust the width, height, exposure, contrast, color saturation and other features as you want. Each optimized image is kept high resolution as the original image.

RIOT

RIOT is short for Radical Image Optimization Tool, and it is free to all users. This powerful tool is dedicated to helping people adjust images and keeps minimum filesize. There are two types of interfaces offered to you, including the dual view and single view. With the side by side interface, you are able to compare the original image and optimized image in real time.

Additionally, it is also lightweight and extremely simple to use, with which you can control the number of colors, metadata settings, compression and many more. Three image formats including JPG, GIF and PNG are available for your file.

Online Image Optimizer

The Online Image Optimizer is released by dynamicdrive.com, used to optimize JPGs, GIFs and PNGs with ease and make all images load on your website as fast as possible. What's more, it allows you to change the image file type as you need and upload up to 2.86MB image size. Once entering the interface, two uploading methods are available here. One is to enter the URL of an image, and the other is to upload one from the computer.