WhatsApp compresses the images, and hence most users opt to other methods for transferring high quality pictures. To resolve this issue, WhatsApp has now made it possible to share HD images through their chats, as announced by Meta CEO Mark Zuckerberg in a Facebook post.

source https://www.gadgets360.com/how-to/features/whatsapp-hd-images-high-quality-send-chats-easy-steps-4313595#rss-gadgets-all