Image Size refers to two parameters:
- Dimensions (e.g., 1024 by 680 pixels)
- File size ( e.g., 350 kilobytes)
Both parameters are important since a smaller image (by dimensions) doesn't always mean a smaller image file size. At the same time smaller image file size doesn't always mean worse image quality or smaller image by dimensions.
Proper Image File Size
Big file size can lead to slower page load which in its turn can lead to higher bounce rate, bad user experience and downgrade in Google ranking.
What is bounce rate?
Bounce rate is the percentage of visitors to a particular website who navigate away from the site after viewing only one page.
Too small image file size can make image quality unattractively low.
What is the proper image file size?
An image file size is better not to be over 500 kilobytes. The minimum file size is limited only to what you find visually appealing.
Proper Image Dimensions
Proper image dimensions are more complicated to define.
The short answer is that any image dimensions which look good for users are ok.
The numbers below are usually recommended to user but not a must.
Website images:
- Full-width images should be 2400x1600 px
- Inside content images: horizontal - max width 1500 px, vertical - max width 1000 px
- Slideshow images should be 1500 px height
- Blogpost image - 1500 px width
- Favicon image - 300x300 px
Facebook images:
- Facebook profile pic - 180x180 px
- Cover image - 820x312 px
- News Feed Post - 940x788 px
- Feed ads - 1200x628 px
- Facebook Stories - 1080x1920 px
- Facebook Event Cover Image - 1920x1080 px
Instagram images:
- Instagram profile pic - 110x110 px
- Post images - 1080x1080 px
- Oblong posts (portrait or landscape) - 1080x1350 px
- Feed ads - 1080x1350 px
- Stories Posts and Ads - 1080x1920 px
Twitter images:
- Twitter profile pic - 400x400 px
- Cover image - 1500x500 px
- Tweet images - 1024x512 px
- Twitter card and Ad Image - 800x320 px
LinkedIn images:
- LinkedIn profile pic - 400x400 px
- Cover image - 1536x768 px
- Feed and Sponsored post image - 1200x627 px
Pinterest images:
- Pinterest profile pic - 165x165 px
- Pins and Promo Pins - 564x846 px (Pinterest recommend 600x900 px)
