1. kraken.io – If you need an online application to compress image formats like JPEG, PNG, GIF, SVG to a point where the image doesn’t loose on quality, but the size comes down by really good amount. I tried with an already compressed image using a desktop application, Kraken compress that file to an extra 10% without losing on quality. Firefox and Chrome extensions are also available for this application.
2. smush.it – It is a very popular online application to compress images. There is an up-loader as well as URL box to provide the image. There is no way to enter the output quality, the application auto-optimize the image by compressing the same to a limit.
3. imageoptimizer.net – You can upload the image from your computer and give the image quality and size that you want after processing. It gives you some control (very limited) on the output and compression ratio.
4. compressjpg.com and compresspng.com – For more control on the last result’s quality, I would suggest you to use this application. Once you upload the image from computer, a slider appears to auto-control the quality of the last image. There is a preview panel showing the changes according to the quality slider change, and there you can see the final image quality before downloading the image. There is a zoom-in/out feature also available in preview where one can see the quality of the image pixel by pixel. Application is available on different domains for JPG and PNG images.
5. punypng.com – To compress PNG files, you can try this online tool. Upload the image (PNG only) from local computer and get the compress version of the image.
6. tinypng.org – Another quick tool for PNG images for compressing the image to best level without compromising on quality.
7. jpegmini.com – To compress JPEG images up to 5X, you can checkout this tool. There is a up-loader to upload the image from local computer and process the same.
1. IrfanView (Windows only) – To compress single or multiple images (bulk processing), this is a must have tool. I use to compress all the pictures that I took using my Digital Camera (18MP) before uploading the same on social media sites. You get full control for resizing and image quality for compressing the images.
2. Trimage (Cross Platform – Linux, Windows, Mac) – It is a cross-platform tool for optimizing PNG and JPG files. You can find the details on its GitHub page.
3. ImageOptim (Mac only) – A Mac application to optimize or compress the images.
4. GimpShop (Windows, Mac, Linux) – A very popular and free alternative of Adobe Photoshop with so many tools to work on images including compression tool.
If you are using self hosted WordPress CMS for websites, there are multiple image optimizer plugins to auto optimize the media library images to a set quality. It helps in making the website faster and SEO friendly (as recently Google updated its algorithm to include the site’s page-load time as an important factor for SEO). There are many free and paid plugin to optimize images, here are few working and well-tested plugins.
2. WP Smush.it
4. WP Boyka
Do you use any other image compression tool to optimize the pictures? Share the name of your favourite application for image optimization and also your experience about the post compression results.