PNG, a lossless image format, works well for text and graphics, like screenshots. The one drawback to PNG is that the resulting file size can be larger than JPEG files. PNGGauntlet, a free Windows program, can help reduce the size of PNG files and since PNG is lossless, compressing it will have no impact on its quality.
To use PNGGauntlet, first make sure you have Microsoft .NET framework 4.0 installed. When you’re ready to start, add the PNG files you want to compress by dragging them over to the screen or clicking on the Add Images button. Next, select the Output Directory, then click the Optimize! button.
The screenshot above (click to enlarge) was shrunk down to 88 percent of its original size and no quality was lost.
From the above screenshot alone, it shouldn’t be difficult to eyeball the general procedure. Navigate to any folder within Windows Explorer and drop the images that you’d like to optimize into PNGGauntlet’s interface.
Optionally, you can click Add Images to bring up a prompt that will allow you to manually browse your hard drive. Make sure you select an output directory, also. While we’ve got everything ready to go, now would be a good time to go over the configuration of PNGGauntlet.
Click Options under the Tools menu.
If you don’t have the beefiest machine, running compression on lower priority may be best. The last option on this window is in respect to the fact that PNGGauntlet will also convert JPG, GIF, TIFF, and BMP files to the PNG format.
The other tabs in this window will allow you to configure options to each plugin that PNGGauntlet uses.
As you can see, the options get very specific for PNGOUT. OptiPNG will allow you to set a level of compression and DeflOpt will allow you to preserve your images’ metadata.
After you’ve tweaked everything to your liking, go back to the main window and you can now feel safe to click Optimize.
I went ahead and hit Google for a picture of a cat in PNG format. Here’s what we’ve managed to do:
In just a click, PNGGauntlet was able to compress this image by 37%!
Here are those two images:
If you can’t tell the difference, it’s because there is no visual difference! The PNG on the left is about 45 KB larger, though. This compression was made using the default options of PNGGauntlet.
Tutorial source from Craig Snyder