I usually work in PNG in most of websites that are sliced at Artmov. PNG offers me a great quality, but with the price of higher sizing. But the high sizing in PNG images can be easily optimized with several online tools (Smush.it) or, even a application for Windows folks (PNGGauntlet).
I’ve put to test both applications that I’ve worked over many website sliced. The online tool, Smush.it and an application installed on a Windows operating system, PNGGauntlet.
Smush.it, unfortunately, remove it’s functionality to upload the images for optimizing, leaving only the where you need to write down the URL path to the image. And since many website are sliced on a local computer and later on uploaded for testing, a good solution will be an application that can be installed on a computer or uploading the images fast.
A PNG image of 439.96 KB has been tested, both on Smush.it and on PNGGauntlet. The results are below.
| PNG Image (example) | Time to Optimize | New Size of PNG (% Savings) | |
| Smush.it | 439.96 KB | Fast | 46.46 KB (89.44%) |
The 439.96 KB PNG image optimized by Smush.it:
- Resulting Size: 46.46 KB
- Saving Size: 393.50 KB Saving
- Saving in %: 89.44
13 PNG images, with a total of 2.07 MB in size, with only one GIF of 47 bytes.
| Compression Strategy | PNG Image (example) |
Time to Optimize | New Size of PNG (% Original Size) |
| Xtreme! | 439.96KB | Slowest | 49.31 KB (11%) |
| Intense | 439.96 KB | Slow | 49.55 KB (11%) |
| Longest Match | 439.96 KB | Fast | 55.75 KB (13%) |
| Huffman Only | 439.96 KB | Faster | 378.30 KB (86%) |
| Uncompressed | 439.96 KB | Fastest | 2382.37 KB (541%) |
- Xtreme! Strategy: 2.07 MB into 139 KB
- Intense Strategy: 2.07 MB into 140 KB
- Longest Match Strategy: 2.07 MB into 189 KB
- Huffman Only Strategy: 2.07 MB into 754 KB
- Uncompressed Strategy: 2.07 MB into 1.84 MB
I don’t take in consideration the last strategy, the Uncompressed Strategy. The 541% showed in a red color / probably an error or the PNG couldn’t be optimized properly.
The result.
Smush.it successfully optimized the PNG file into a 46.46 KB and PNGGauntlet into a 49.31 KB (considering the slowest strategy). The difference between is only 2.85 KB.
Smush.it can be added as an add-on for Firefox browser. Download YSlow.
Conclusion.
I’ll go with Smush.it and PNGGauntlet for optimizing the PNG images.
PNGGauntlet’s biggest advantage is that I can easily optimize the images from my local computer without going online everytime I need a smaller size for PNGs.
Smush.it’s advantage is that it’s installed as an add-on on Firefox, along with several add-ons that I use to slice websites (Firebug, Web Developer Tool, etc)
Please note that I’ve taken in consideration and in testing only these 2 applications to optimize PNG images. Below are links to several other applications that can optimize PNGs – choose what’s best suited for you.
[1] 10 Free Tools to Optimize  and Compress PNG Images
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