Three perfect image optimizers for SEO

What is this - a perfect image optimization tool for SEO?

For me the perfect image optimization tool must have following features:

• This image optimizer is not a kind of hipster online tool, but the old good installable software,
• This image optimizer is free - not a kind of shity shareware, which means it would be free, but indeed isn't,
• User can setup an optimization level,
• The tool must do batch image compression - real SEO ninjas don't have much time,
• This image optimizer must, no - it MUST understand nested folders and
• it MUST be able to save optimized images in the same nested folder/subfolder structure,
• This tool, again, MUST be able to save optimized images without to change the file type,
• This tool should be able to resize images saving the width/height ratio.
• And, of course, it must do its compression job well ;)

Do i want too much? No, i believe, it isn't too much.

I will not explain, why image compression is substantially important for your website's rankings. Just one sentence: images are the most heaviest static asset type on ANY website. Do you still don't want to compress them? No prob, just as you wish. But why are you still here?

For non-ignoramuses among us: yes, such tools actually exist - they aren't just a subject of SEO fable tales. I know even three tools, which are able to accomplish every single task i listed above. Want to know more? Let's go →
To cut the long story short:

Testing environment:

• nested folder structure of 32 subfolders with different nesting, the highest folder's name is wp-content, then are going /plugins/, /themes/ and /uploads/, so you know, what is this about:)
• ca. 1.000 different images: gif, png, jpg,
• Source file size: 13,1 Mb

This nested folder structure with images i've got through downloading them with HTTTrack from a client's website - i thought it goes faster as to get FTP access ;)

Image optimization tools - only a few, but perfect

Mass Image Compressor

• installable or portable,
• ZIP-size with both files: 677 kB,
• optimization level: 50%
• optimized output size: 8,5 Mb (saved ca. 35%)

Caesium Image Optimizer

• installable or portable,
• installable file size:15 Mb
• optimization level: 50%
• optimized output size: 7,2 Mb (saved ca. 45%)

Caesium Losless Optimizer

• installable or portable
• installable file size: 18 Mb
• Optimization level - no setup, lossless optimization by algo
• optimized output size: 10,9 Mb (saved ca. 16%)

All of three tools do a perfect batch image optimization with saving of input file types and nested folder structure.

Congratulation! Now your know everything about perfect tools for batch image compression ;)