Pagespeed still tells me to 'Optimize Pictures'

Some of those need resizing first. You need to take care of that before compression. Since the Hammy plugin isn’t working for you, you need to either manually resize and update those images, or register a resize using Simple Image Sizes and regenerate thumbnails. That’s all detailed on that blog post you already read, and which method you choose depends on how many image you have, and how many of each resize are needed. For example, if you have 5000 images, but only need 5 of them to have a 200×290 resize, I would do them manually. But if you have 400 images, and have 30 that needs a particular resize, I’d go with the Simple Image Sizes and a thumbnail regenerate.

For the rest of them, it looks like those are probably being generated by other plugins, so you’ll likely need to add the full path to wp-content/uploads/ into Folders to Optimize and run a Scan & Optimize. I suspect the ones with wp.com urls are from the jetpack plugin, but hard to say for sure without knowing exactly where they are displayed, by what plugin, why they are being processed by wp.com, etc.

Great news: I’ve got Hammy working on my blog ??
I’m not quite sure why I would need to resize these images. For example: https://www.geekster.be/…12/mitchell-david-tijdmeters-351×185.jpg

My theme need the image in that size. Same goes for: https://www.geekster.be/…9936889_3124391851846660067_n-110×96.jpg

I added the uploads-folder to ‘Folders to Optimize’
Running now as we speak ??

Little update: the plugin tells me:
mitchell-david-tijdmeters-110×96.jpg – Reduced with 0.0% (228 B) – Already optimized

While Google PageSpeed keeps telling me:
Het lossless comprimeren van https://www.geekster.be/…/12/mitchell-david-tijdmeters-110×96.jpg kan 657,9 KB besparen (een besparing van 97%).

Odd, isn’t it?

Using cloudflare, another CDN, or any caching? I’ve often seen caches throw the results off.

I’m using ‘W3 Total Cache’ but only recently and I always clear cache or even deactivate when changing settings of any plugin.

It’s possible that a plugin is generating that image on page-load without using the wp_image_editor class. If the plugin isn’t also properly checking it’s own cache, you’ll end up with an image that will get ‘un-optimized’ when someone views the page, no matter how many times you optimize it.

Ow, man.

Then my guess would be that it’s the plugin generating the widgets in my footer…
But that’s from my custom theme, I’m gonna check it with the developer if there’s anything he can say that might help us