Here are the specifications for each social media platform you can post to from Optimal Blue's Social Cloud. The following specifications will help you create your posts and avoid any issues posting to the various social platforms.
Facebook 
Image:
You can share up to 10 images in 1 post
10 MB max size
1200x630 max resolution
Recommended Image Size for posts—1200 x 630
Carousel: 1200 x 1200 minimum-600 x 315
Video:
Titles need to be 125 characters or less
1GB max
20 min max length
MP4
1080x1350 recommended size
Text/Caption:
For image and video posts, captions can be up to 63,000 characters
For posts that share a link as the "media" of the post, captions can be up to 1000 characters
Posting to groups are no longer allowed per Meta's API
Instagram 
Image:
You can share up to 10 images in 1 post
Images should be 1080x1080px or 1080x1350px maximum, 1080x566px for horizontal content
Recommended Image Size for posts–width of 1080 pixels
Landscape: 1080 x 566
Portrait: 1080 x 1350
Square: 1080 x 1080
Supported aspect ratios: Anywhere between 1.91:1 and 4:5
Video:
3 seconds minimum, 15 min maximum length
9:16 aspect ratio, 1920 maximum vertical, 1080 horizontal pixels max
1GB max
Maximum bitrate: We recommend 5 MB/second to avoid overloading Meta's servers, but they do accept up to 25 MB/second
MP4 file type
Video content will post as an Instagram Reel by default
Text/Caption:
2200 character maximum
30 hashtag limit
Links will post, but will post as text (alternate is using "link in bio" on Instagram)
Story Post:
Image:
Images should be 1080x1080 or 1080x1350 maximum
Aspect Ratio: 9:16
Unable to tag accounts/users in Story post
Steps to creating a Story post here
Must be a Business Instagram account
Video:
Aspect Ratio: 9:16 is recommended to avoid cropping or a backgroundResolution: Max 1920 horizontal pixels x 1080 length pixels
LinkedIn 
I
mage:
1080x1080 resolution recommended
9 images max for 1 post
Recommended Image Size for posts—- 1200 x 627
Carousel: 1080 x 1080
Video:
10 minute max length
200 MB max
Title needs to be 400 characters or less
MP4 file type
Text:
3000 character maximum
30 Hashtags maximum
Twitter 
Image:
1600x900 resolution max
4 images per post max
Video:
2 min 20 second max length
512 MB max
1280x1024 resolution max
MP4 file type
Text:
280 character maximum
Youtube 
Image:
Not Allowed
Video:
512 MB max
MP4
100 character title max
Shorts:
For your video to be posted as a YouTube Short, it must:
Be 60 seconds or less
Be in the vertical format with an aspect ratio of 9:16 and a resolution of 1080x1920 pixels
YouTube also categorizes square videos under 60 seconds as a Short:
The aspect ratio must be 1:1 with a resolution of 1080 by 1080
Due to the square cropping, the video will be posted with a black bar at the top and bottom
The black bars at the bottom leave space for viewers to easily see the video title, channel name, and subscribe button, so use them at your discretion
Text:
15 hashtags max
5000 character caption max
Google Business Profile 
Image:
1 image per post max
1080x1080px resolution recommend
Video:
30 seconds maximum length
MP4 file type
Text:
1500 character caption max
Follow Google posting guidelines here
TikTok 
Image:
Not allowed
Video:
10 minute maximum
1080x1920 resolution max
MP4 file type
Text:
150-character limit for caption
Pinterest 
Image:
Only single image posts
Recommended Image Size for posts—- 1000 x 1500
For square posts(pins): 1000 x 1000
Video:
60 second max
1080x1920 resolution recommended
Must be a business Pinterest account
Text:
20 hashtag limit
Cannot replace the cover image when sharing an article as the "media" of the post
Cannot contain links in the caption
Caption must be 500 characters or less