Optimizilla!

ImageOptim is excellent for publishing images on the web (easily shrinks images “Saved for Web” in Photoshop). It's useful for making Mac and iPhone/iPad applications smaller (if you configure Xcode to allow better optimization). ImageOptim removes EXIF meta­data, such as GPS position and camera's serial number, so that you can publish images without exposing private information (but there's an option to keep the meta­data if you need it).

Saving images for web/email/other media with the best compression ratio and quality is a difficult task if you don’t have the right tools. Choosing the right format then choosing the right parameters are the key factors of smaller files. Previewing the resulting image and the projected filesize will help the user choose the best settings. This kind of image optimization software is often called “Save for web”.

TinyPNG uses smart lossy compression techniques to reduce the file size of your PNG files. By selectively decreasing the number of colours in the image, fewer bytes are required to store the data. The effect is nearly invisible but it makes a very large difference in file size!

JPEGmini is a patent-pending photo recompression technology, which significantly reduces the size of photographs without affecting their perceptual quality. The technology works in the domain of baseline JPEG, resulting in files that are fully compatible with any browser, photo software or device that support the standard JPEG format.

With Image Optimizer you can losslessly optimize your PNG, JPEG and GIF files and thus save your bandwidth and your users' time! Kraken recompresses images with blazing speed and strips metadata with image quality intact.

optimus.io offers lossless compression of images available with a WordPress plugin and via API. Benefits: - The file size will be reduced but the image quality remains the same- Bulk optimization- Conversion also to WebP available

WP Smush strips hidden, bulky information from your images, reducing the file size without losing quality. The faster your WordPress site loads, the more Google, Bing, Yahoo and other search engines will like it.

Photo Size Optimizer for Mac:

Optimize pictures without quality lossless.

Lossless Photo Squeezer for Mac is a professional image size compressor which will reduce your PNG, JPEG and GIF photos and images size with LOSSLESS quality. You can optimize all your photos to save much hard drive space, web space and share full-resolution photos online more faster.

IMAGEmini, a powerful photo resizer and optimizer, allows you to optimize all your photos by 80% ~ 20% comparing to their originals while keeping their original resolution, quality and png, jpg, gif formats. With IMAGEmini, you can save huge space and share full-resolution photos with your friends much faster.

A Mac app and Chrome extension that optimizes/compresses images and PDFs. Tinybeest also converts file formats and resizes images for the web.

ShortPixel is an image optimization API and WordPress plugin that helps improve your website performance. Both lossy and lossless compression available.

ImageSizer is an application built to resize, optimize and rename a batch of jpg images producing a zip file containing the images. ImageSizer also allows users to resize images that are greater than 2880px by 2800px, however the resized images cannot be greater than this size.