Image CDN resize

Hi there,

Do you mean you’re creating separate thumbnail versions of images you upload, so you’re uploading the full-size image as well as a thumbnail image?

That shouldn’t be necessary regardless whether you use our CDN or not: You can specify a size for thumbnail images in Media Settings at WP-Admin ->Settings ->Media, and when you insert an image into a post/page and select the Thumbnail size setting, WordPress should automatically display the image at that size on your site.

Settings Media Screen

But the CDN does create its own thumbnail-sized version of any image file you upload, yes, and then serves that file if it detects the browser is requesting an image with those dimensions.

Yes,

Wordpress creates a separated resize image for every thumbnail dimension needed. In this way, WordPress always uses the right image saving bandwidth and speeding up the website.

Obviously, I’m using a lot of Gb to store the same image resized for every thumbnail dimension (my theme has different thumbnails dimensions for featured image post type). This is why I was asking if Jetpack automatically detect the right dimension and cut the image to fit in it.

Another thing, I’m using WebP Express, a plugin that automatically collects and serves the image in .webp format. As soon as I’m using Jetpack CDN that, from what I’ve understood, automatically convert images in webp if the browser support it, I no more need to convert and serve it from my server, right?

• This reply was modified 5 years, 1 month ago by nicocaldo.

WordPress creates a separated resize image for every thumbnail dimension needed.

WordPress does not create multiple copies of the file in the media library that I know of. The media settings I refer to are size presets you select when inserting an image into a post.

If your site is automatically creating a duplicate file of images you upload at a thumbnail size, something else is doing it.

(my theme has different thumbnails dimensions for featured image post type)

What theme are you using? It sounds like this might be a feature of your theme, in which case you’ll have to contact their support to ask how to disable it.

As soon as I’m using Jetpack CDN that, from what I’ve understood, automatically convert images in webp if the browser support it, I no more need to convert and serve it from my server, right?

Correct. If Jetpack detects your site is being viewed on a device and browser that supports webp, the CDN will serve a webp version of the image instead.

https://jetpack.com/support/site-accelerator/#how-site-acceleration-works

WordPress does not create multiple copies of the file in the media library that I know of. The media settings I refer to are size presets you select when inserting an image into a post.

If your site is automatically creating a duplicate file of images you upload at thumbnail size, something else is doing it.

They’re not visible on the media library but, from what I’ve understood and checked the upload folder inside wp_content, I have different images, correctly resized, for every size needed by the theme.

For instance, if a post has a featured image that is displayed with a size of 400×200 and I upload an image bigger than that, WordPress automatically cut and resize the image to fit with that specific size to save bandwidth and increase the loading speed

I think it uses this approach https://developer.www.ads-software.com/reference/functions/add_image_size/

Huh, I’ve never noticed that, but some searching reveals WordPress has been doing this since 2014!

Based on that article you should set all the media size settings to zero, and if your theme is also generating image versions, modify your theme to stop it from doing it (I’d contact your theme’s support for help with that, though, as that snippet from the article might be outdated by now). Just note that

But I asked our team about this and it appears I misunderstood this aspect of the CDN: our CDN isn’t a replacement for this. Our CDN only caches an image at the moment it’s used in a post. In other words, the CDN uses the sized version generated by WordPress, which is inserted at that point.

I hope that makes sense, but let me know if you have any more questions about this.

the CDN uses the sized version generated by WordPress, which is inserted at that point.

That’s what I needed to know! Thanks.

That’s great. I have marked this thread as resolved. Be sure to reach out with further questions in the future.