Supported posts:
Facebook
Supported post types: Status updates, links, single & multi-photo posts (no limit on the photos per post), albums, videos, Reels, carousels, and GIFs.
Limitations:
Photos can be of any format and size. GIFs need to be less than 4 MB.
Link carousels can have up to 10 slides.
Videos can be of any format, but need to be less than 20 minutes long and less than 1 GB.
Reels can only be between 3 seconds and 90 seconds long, and have a size no bigger than 1GB.
Instagram
Supported post types: Single and multi-photo/carousel posts (up to 10 photos), single video posts, Stories, and Reels.
Limitations:
Photos, regardless of the post type, can be of any format, but need to have a minimum resolution of 320x320 pixels, and be less that 8 MB. They will be automatically cropped if they're not within the 1.91:1 and 4:5 ratios.
Videos, except reels, can only be between 3 and 60 seconds long, and have a size no bigger than 100MB.
Carousels can be up to 10 photos. At the moment, videos cannot be included in a carousel post.
Stories can be posted automatically or with the help of a semi-automated notification/reminder system. For stories that are published automatically, you can upload one photo or one video. For stories that are sent via push notifications/reminders, you can upload up to 10 photos or one video.
Reels can only be between 3 seconds and 15 minutes long, and have a size no bigger than 1GB. Required aspect ratio is between 0.01:1 and 10:1 but we recommend 9:16 to avoid cropping or blank spaces.
Only reels with durations between 5 and 90 seconds and aspect ratios of 9:16 will appear in the Reels tab on Instagram, otherwise they will be posted on the Feed.
X (formally known as Twitter)
Supported post types: Status updates, links, single and multi-photo posts (up to 4 photos), videos and GIFs.
Limitations:
Photos can be of any format, but need to be less than 5 MB and have a minimum resolution of 4x4 pixels.
GIFs need to be less than 15 MB and have a resolution between 4x4 pixels and 2048x2048 pixels.
Videos can be of any format, but need to be less than 140 seconds and less than 512 MB.
LinkedIn
Supported post types: Status updates, links, single and multi-photo posts (up to 9 photos), videos, GIFs, and PDF Carousels.
Limitations:
Photos can be of any format and there's no limit on the size.
Videos can be between 3 seconds and 10 minutes long and up to 1 GB. They will be posted natively on both LinkedIn Personal Profiles and Company Pages.
GIFs need to be less than 8 MB and will work on both LinkedIn Personal Profiles and Company Pages.
PDF Carousels can contain up to 100 photos per carousel post. They cannot be mixed with GIFs or Videos as it's not supported by LinkedIn's API. You can upload photos or documents (PPT, PDF, DOC) to Publer and then share them as a PDF carousel.
Polls and Articles are not supported by LinkedIn's API.
Google Business Profile
Supported post types: Updates, events, and offers with a single-photo.
Limitations:
Photos need to have a size between 10 KB and 5 MB and a minimum resolution of 250x250 pixels.
Pinterest
Supported post types: Single-photo posts, carousels with up to 5 photos, and single-video posts.
Limitations:
Photos have no limitations.
Carousels will be automatically cropped based on the first photo's aspect ratio.
Videos need to be between 4 seconds and 15 minutes long.
YouTube
Supported post types: Videos and Shorts.
Limitations:
Videos can be up to 12 hours long and 1 GB.
Shorts need to be shot vertically and be up to 60 seconds long.
To post YouTube Shorts via Publer, simply add the hashtag #shorts in the title or the description of the video as shown in this thread.
Telegram
Supported post types: Status updates, links, single and multi-photo posts (up to 10 photos), videos and GIFs.
Limitations:
Photos can be of any format, but need to less than 10 MB.
GIFs need to be less than 50 MB.
Videos can be of any format, but need to be less than 50 MB.