As a web optimizer, you might now that the Internet’s main bloatware is images. There are so many tools out there for lossless PNG optimization. Which one is the best now?
;tldr Zopfling
Testing
I took a sample .png image sized 46966 bytes and ran it across well established optimizing software. Each time maximum compression/optimization flags were passed.
What I’ve tested:
pngout(a less known optimizer with closed source deflate compression algorithm that beats most known tools)optipng(an often choice for most)pngcrushzopflipng(the new folk by Google, actually a companion tool to their zopfli library)
Results
| Tool name | Flags | Result size, bytes |
|---|---|---|
| pngout | 44519 | |
| pngcrush | -brute -reduce | 46813 |
| optipng | -o7 | 46657 |
| zopflipng | -m | 43291 |
Install and use Zopfling
Without much further ado, I will tell you how to use Zopfling to crunch your PNG images without loss of quality.
In CentOS/RHEL, we have made it available for easy install. Setup our repository, then:
yum -y install zopfli
That’s it! Now you can run zopflipng -m /path/to/your.png /path/to/your_optimized.png to crunch size without losing a bit of visible information.