A Guide to Social Media Posting In 2021

Social media has taken a significant part of businesses and consumers today. Social media platforms have connected brands with communities. They have changed the way people communicate, discover trends, find news, and shop for products and services. As physical stores were forced to close in 2020, social media became the key for marketers to bounce back. Yet, everything is constantly changing. Certain elements in social media also change to cope with the trends. Below is the latest guide to social media posting in 2021. 

What Is Social Media?

A social media agency Hong Kong defines social media as a community of Internet users who engage and share different ideas, thoughts, and contents. Users commonly sign up for individual profiles to be able to network with others. Social media platforms are initially intended to promote connections between family and friends. Later, brands and businesses realized the power of social media in marketing. According to a digital marketing speaker Hong Kong, the top 3 social media sites for marketing are:

  • Facebook
  • Twitter
  • Instagram

Guide to Social Media Posting

People commonly post images, text, and videos on social media platforms. Below are the latest standards when posting these types of content on the top social media platforms of 2021.


A future-proof brand strategy on Facebook is uploading high-quality images. That is why Facebook is constantly updating its design and image dimension to format the best results ever. This 2021, the image sizes for Facebook images are the following:

  • Cover Photo = 851 x 315 pixels
  • Facebook Ads = 1080 x 1080 pixels
  • Panorama or 360 Degree Photos = 30,000 to 135,000,000 total pixels
  • Post and Timeline Photos = 1200 x 630 pixels
  • Profile Photo = 170 x 170 pixels
  • Stories = 1080 x 1920 pixels

Facebook also recommends uploading JPG or PNG images. These types of image files have a faster loading time. PNG files work best on cover photos and profile pictures with logos or text.  

Tweets with images get 3x more engagements than tweets without images. To get more click-throughs, likes, comments, and retweets, here are the right image sizes for Twitter in 2021.

  • Ads = 600 x 335 pixels 
  • Card Images = 120 x 120 pixels
  • Fleet Images = 1080 x 1920 pixels 
  • Header Photo = 1500 x 500 pixels
  • In-Stream Photos = 1600 x 1900 pixels 
  • Profile Photo = 400 x 400 pixels

The best way to future-proof Twitter images is to use these maximum sizes recommended. Keep in mind that the display of Twitter images also depends on the device use – desktop or mobile. 

Instagram is a popular photo-sharing app that supports both horizontal and vertical images. The platform’s image dimensions are a little trickier than that of Facebook. But these latest guidelines can ensure high-quality IG images: 

  • Ads = 1080 x 566 pixels
  • Carousels Photo = 1080 x 566 pixels for landscape; 1080 x 1350 for portrait; 1080 x 1080 pixels for square photo
  • Feed Photo = 1080 x 566 pixels or 1080 x 1080 pixels or 1080 x 1350 pixels
  • Profile Photo = 320 x 320 pixels
  • Stories = 1080 x 1920 pixels
  • Thumbnails = 161 x 161 pixels

Even though Instagram supports square photos, they are displayed in a circle. So, make sure to center the element in focus on the image frame to avoid cropping issues.


Brands compete with thousands of other pages on Facebook, Twitter, and Instagram. Besides, the audience has a limited attention span. So, marketers need to do everything to grab the audience’s attention and stand out. An effective way to do it is by following the ideal characters recommended by these top social media platforms. 

The ideal length of a status update on Facebook is 40 to 80 characters. Make it short but sweet. Studies showed that Facebook posts with less than 80 characters received 88% more engagement than posts with longer text. For Facebook ads, the ideal number of words for a headline is 5 and 14 words or less for the contextual message of the ad. 

Twitter, on the other hand, limits the number of characters for a tweet to 280 counts. But the sweetest spot for a tweet is around 100 characters. They got 17% more engagement than longer tweets.

The character limits of an Instagram post are fewer than Facebook and Twitter. This is because the platform mainly focuses on the sharing of photos and videos. The ideal length for an Instagram caption is 138 to 150 characters. For Instagram ads, it should be around 125 characters. Instagram allows adding more than 20 hashtags in a post. But brands using 5 to 10 hashtags in an IG post get better visibility.


There are different ways to deliver video content among social media platforms. That is why it is very tricky for a video marketing agency Hong Kong to optimize video content. 

Among regular feeds, Facebook recommends uploading videos in MOV or MP4 format. The minimum width should at least be 120 pixels. Facebook supports horizontal videos with an aspect ratio of 16:9 and vertical videos with an aspect ratio of 9:16.  

Twitter can best handle videos captured on mobile devices. The platform also recommends uploading videos in MOV or .MP4 formats. The minimum width should at least be 600 pixels for square videos and 640 pixels for horizontal and vertical videos. Twitter supports videos with an aspect ratio of 1:1 and 2:1

Instagram supports 3 video formats with the following aspect ratios:

  • Square videos with a 1:1 aspect ratio
  • Horizontal videos with a 16:9 aspect ratio
  • Vertical videos with a 4:5 or 9:16 aspect ratio

MOV and MP4 format are still the recommended video files for Instagram. Regarding the number of pixels, Instagram recommends the following:

  • Carousel videos = 600 X 600 pixels
  • In-feed videos = 500 pixels
  • Stories video ads = 500 X 889 pixels
  • IGTV = 1080 X 1920 pixels

In general, social media platforms recommend uploading the shortest text possible with the highest quality images and videos.