My issue with the various apps and services that compress images (excepting FileOptimizer) is that they tend to fall into two distinct categories; online services (which means uploading images and then deflating completed files) and locally installed programs which tend to specialise in specific filetypes e.g. PNG or JPG. What I like about FileOptimizer is that I can drag and drop files into the app and my files, no matter the extension, will be compressed and overwrite my original larger files; it’s very simple and works well.
Why FileOptimizer image compression is slow
One thing that is frustrating with the default FileOptimizer install is that PNG files are very slow to optimise. FileOptimizer uses multiple PNG compression apps and PNG is anyway relatively slow to compress so it can take ages for PNG files to be optimised. By default FileOptimizer compresses your PNG files using all of PNGout, Leanify, OptiPNG, TruePNG, pngquant, ECT, APNG Optimizer as well as others. This makes it very slow.
Instructions to speed up FileOptimizer image compression
Fortunately it is simple to safely disable various of the PNG plugins which greatly improves the speed of compressing PNG files whilst retaining great optimisation. Below are the instruction to disable various PNG optimisation plugins from running when you use FileOptimizer:
- Install FileOptimizer.
- Open the newly installed FileOptimizer and then close the program.
- Search your Windows computer for FileOptimizer.ini and open FileOptimizer.ini in a text editor (such as Notepad or Notepad++).
- Search for DisablePluginMask in the FileOptimizer.ini file.
- Replace the entire contents of the line that starts with DisablePluginMask with the following:
DisablePluginMask=pngwolf;advpng;pngout;optipng;truepng ; String. Default: ''. Allow excluding execution of certain plugins. It is case insensitive, and allows more than one item to be specified by using semicolon as separator. - Save the file and close.
In step 4 above I’ve disabled the PNG compression plugins that I found of little optimisation benefit. You of course may disable others as you see fit for your purposes.
FileOptimizer should now run much faster when compressing PNG files. Please let me know in the comments below if you have found this helpful.
Hi Gary, I find your article interesting. I am also into this topic since years and always marveled what the best workflow might be to optimize the images of our ecommerce shop. After starting with the solo command tool under windows, I started to use them with XNview and Irfan under Windows and eventually I found FileOptimizer and used it for a long time for the same reasons you named.
FileOptimizer is meant to compress lossless.
I came to the point where I thought that I should best compress my product images in the shop lossy.
Why? Well, I shoot images with my digicam in top quality and develop them in raw. Then I save them mostly in Photoshop as JPG. Photoshop also offers the option to compress jpg/pngs.
Nearly all images guide on the web say it is ok to use 60-90% JPG compression already in Photoshop export.
Mh,…. you see there might already be a stepping stone.
Most eccormerce systems (also WordPress I think) offer also to compress images when you upload them. Again ….
In a nutshell, I thought it is best to deactivate all these compressing options and let this be done by expert code.
Well, FileOptimizer or Kraken.io.
That said, I came to the conclusion if all previous steps were made in 100% quality I could very well use Kraken with a lossy compression setting.
What do you think?
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Of course, loading speed is essential but best image quality most.
Great to hear that you’re trying so hard to compress images. I’m not a big fan of lossy compression therefore ‘disable’ WordPress Jetpack Photon automatic lossy compression.