The top 5 online image optimization tools were examined and compared.

The top 5 online image optimization tools were examined and compared.

Online image optimization tools allow you to convert between file types and compress images without reducing image quality.

To give you an idea of how much compression is possible, we tried a few different online image optimizers. We’re juggling two pictures here: a JPG (of about 1.3 MB) and a PNG (2.1 MB approx.).

You can see the two optimized images, one from each tool, down below. Before applying any online image optimizer, the original file size is displayed in the top right corner for easy reference.


Compress Now is an excellent image optimization tool that can reduce the file size of JPG, GIF, and PNG images, three of the most common image formats.

One of its other useful features is the ability to customize an image’s compression settings after it has been uploaded. The maximum file size you can upload is 9 MB (9000 KB), which is much larger than either of the examples we provided.

For the experiment, I used a compression level of 65%, and it was nearly impossible to tell the difference between the original and the much lighter compressed version, even with just the naked eye. A slight dulling of the image’s sheen resulted from the compression process. By “smidge,” I mean that if you mixed up the compressed and uncompressed versions and asked me to tell them apart, I might have a hard time doing so.

This online image optimizer has one major flaw: it only outputs JPEGs despite supporting JPEG, PNG, and GIF inputs.

If you don’t mind a drop in quality, Compress Now is the best quality image compressor out there. The numbers are accurate. Check the floor below.


90.97 percent success rate in preserving JPEG images.

90.98% efficiency when saving PNG images (output file is JPEG)

JPEG Optimizer

JPEG Optimizer is a viable option to consider if you only need to compress JPEG images due to its lack of support for PNG and GIF files, as the name suggests.

Image compression on the website can be adjusted from 0% to 99%, but the default setting of 65% should be adequate for the vast majority of visitors. Simply by leaving the defaults alone, I was able to cut the image size in half without sacrificing quality.

Altering the image’s dimensions and maximum size is also possible (the default is 4 MB). After the image has been compressed using the tool, it can be downloaded and used as necessary.


There was a 95.39% success rate when using JPEG images for file saving.

Tiny PNG

Tiny PNG is a dependable tool that can compress JPEG and PNG images with ease and allow you to upload up to 20 images simultaneously. The maximum size for any single file is 5 MB. If you want to download larger files, you’ll need to upgrade to a paid account.

After being compressed, photos can be uploaded to cloud storage services like Dropbox or saved locally. Tiny PNG simplifies things for WordPress users as well, with a free plugin. Check out our previous article for a comparison of image optimization plugins for WordPress.


Almost as many PNGs were saved as JPEGs (92% vs. 8%).


Another straightforward programme for optimising JPEG, GIF, and PNG images. By using Optimizely, you can upload up to 20 pictures. When an image is uploaded, the tool adds it to a queue and automatically applies lossy compression.

The optimization process can be watched in real time as each image is compressed and displayed in a slider. By comparing the compression percentages, you can determine which photos you don’t need to keep and delete them.

If you’re not happy with the quality at which your images have been compressed by default, you can change this by clicking on any image in the slider, scrolling down to see a preview, and making a new selection. Take a look at the examples below:

Once you’re done, you can choose to download individual pictures or a batch.


In comparison to PNG, 91% of JPEGs were saved. can take any image format and convert it into the JPEG format. It’s compatible with more image formats than the average online image optimizer. Your PNG, GIF, SVG, or even PSD files can simply be dropped onto their site for instant use. In order to send you back compressed images, the tool first processes them by converting them to JPEG.

The tool can also retrieve pictures from your Dropbox or Google Drive and send you a zip file with the improved JPEGs.


Number of JPEG images saved: 79.57 percent.

In terms of space, the PNG image file was saved at a rate of 86.48 percent (output is JPEG)