Social Graph: What's app image preview max size is 300KB

[ponsfrilus]

While Facebook allow up to 8 Mo (https://developers.facebook.com/docs/sharing/webmasters/images/#images-in-link-shares), it seems that What's app only displays thumbnail previews for images up to 300 KB.

The home page image is ~800 KB.

When a link preview uses the default image, it works fine because it is ~146 KB.

Here what the preview looks like on What's app web:

Here an example with an image:

Here an example with the default image:

Why this issue?

The code that generate the social graph metas can be changed to use the same image but in a different size, as most of our site generate optimized size of the same image. If available, the preview should use images lesser than 300 KB to ensure that the preview will be displayed on What's app.