While there's no featured image size that fits all sites, WordPress recommends these dimensions: 1920 × 1080: the largest recommended WordPress featured image size. This works best for most themes and social media sites. However, an image of this size may get cropped when shared on social media sites. 1200 × 630: works best for classic themes and sharing on Facebook. 1024 × 512: recommended size for sharing on Twitter.
Refer to these recommended featured image sizes to find the best size for your WordPress site's needs. Use these photo editors that use AI to enhance your images before adding your photos to WordPress.