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?
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.
- Full-width images should be 2400×1600 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 – 300×300 px
- Facebook profile pic – 180×180 px
- Cover image – 820×312 px
- News Feed Post – 940×788 px
- Feed ads – 1200×628 px
- Facebook Stories – 1080×1920 px
- Facebook Event Cover Image – 1920×1080 px
- Instagram profile pic – 110×110 px
- Post images – 1080×1080 px
- Oblong posts (portrait or landscape) – 1080×1350 px
- Feed ads – 1080×1350 px
- Stories Posts and Ads – 1080×1920 px
- Twitter profile pic – 400×400 px
- Cover image – 1500×500 px
- Tweet images – 1024×512 px
- Twitter card and Ad Image – 800×320 px
- LinkedIn profile pic – 400×400 px
- Cover image – 1536×768 px
- Feed and Sponsored post image – 1200×627 px
- Pinterest profile pic – 165×165 px
- Pins and Promo Pins – 564×846 px (Pinterest recommend 600×900 px)