Social Media Post Formats: What You Can Publish on Each Network

When you manage several clients, the slow part is rarely the idea. It is remembering which network takes what: a Reel here, a PDF there, a photo that X accepts and Instagram crops. This guide to social media post formats lists what you can publish on each network from Postilik, with text limits, file counts and recommended sizes in one place. It is written for community managers, freelancers and agency teams, and it complements our page on scheduling posts across your networks. Keep it open the next time a client sends a landscape video for a vertical slot.

Last updated: November 2026. Networks change their rules often, so Postilik checks your post again before scheduling.

Social media post formats at a glance

Postilik currently publishes to ten networks. This table shows what each one accepts when you publish through Postilik, which can be narrower than what the network's own app allows.

Recommended sizes for each network

These are the sizes that display best. Postilik's image editor has presets, so you can crop for the target network instead of leaving that to the platform.

How to use each network

Instagram

Every Instagram post needs an image or a video; text alone is refused. In the feed, Postilik keeps images between 3:4 and 1:1, the formats that suit the profile grid, and 9:16 is for Reels and Stories. For the full workflow, see our guide on scheduling Instagram posts and the Instagram scheduler page.

Facebook

Facebook is the most flexible: you can post text alone, media alone, or both. One point often surprises clients: several images appear as an album, not as a swipeable carousel. Swipeable carousels are an advertising format on Facebook, so do not promise one in an organic post.

TikTok

Send either one video or a set of photos, never both. Videos run from 3 seconds to 10 minutes. TikTok has no default audience setting, so for each post you choose who can see it and confirm before it goes out. Our TikTok guide for small businesses covers what to film.

LinkedIn

LinkedIn takes text, images and video, plus its PDF carousel, which shows a document page by page. A PDF post goes to LinkedIn alone, so deselect other networks for that post. Our guide to LinkedIn for B2B companies explains when this format earns its effort.

X

You have 280 characters and up to four media files. Count hashtags and links in that limit, which is why text written for LinkedIn never fits here without rewriting.

Threads

Threads allows 500 characters. It reads like a conversation, so short, direct text works better than a recycled caption.

YouTube

YouTube needs exactly one video, with a title of up to 100 characters and a description of up to 5,000. Shorts are vertical and last up to three minutes. Unverified channels are limited to 15 minutes per video, so check the channel before you promise a client a long upload.

Pinterest

Each pin holds one image or one video. Vertical 2:3 images take up the most room in the feed.

Google Business Profile

You can publish a text update with one image, with a minimum size of 400 × 300, and video is not available. It matters most for shops, restaurants and practices that customers look up on Maps. See our guide on posting on Google Business Profile.

Slack

Slack is different from the others: you publish a message to a channel rather than to a public audience. It suits internal announcements, or keeping a client's team informed about what goes live.

Reels, Stories and carousels: the exceptions

• Reels are available on Instagram and Facebook, and each one contains exactly one vertical video.
• Stories are available on Instagram and Facebook, and each one contains one image or one video. Stories do not display your text, so put the message inside the visual.
• Carousels need at least two files. They work on Instagram and on TikTok as photos, and on LinkedIn as a PDF.

If you choose a format that a selected network does not accept, Postilik warns you before scheduling, so you do not find out from a failed publication.

After publishing: messages, comments and reviews

Publishing formats are only half of the picture. The social media inbox brings private messages from Instagram and Facebook together, along with comments from Instagram, Facebook, LinkedIn, Threads, X and YouTube, and reviews from Google and Facebook. Availability depends on your plan and on the account type.

Which networks are coming soon

Snapchat, Reddit, Bluesky, Telegram, Discord and WhatsApp appear in Postilik as coming soon. You cannot connect them or publish to them yet, so do not build a client plan on them for now.

From one idea to every format

1. Start with the idea, not the file. Decide what the post must say before you choose a format.
2. Choose the networks that fit the client. Not every client needs all ten.
3. Shoot vertical first. A 9:16 video is the base for Reels, TikTok, Shorts and Stories.
4. Crop images per network. Use the editor's presets instead of one compromise size.
5. Generate a version for each network. Postilik writes text and hashtags per network, and you read each one.
6. Check the preview, then schedule. Fix anything flagged, and set the time in the client's calendar.

If you run this for several clients, our page for social media agencies explains how to keep their workspaces separate.

Common format mistakes

• Writing text in a Story. It will not be displayed, so place it in the image or video.
• Promising a Facebook carousel. Organic posts with several images appear as an album.
• Mixing a video and photos on TikTok. A post is one or the other.
• Adding other networks to a PDF post. The PDF carousel works on LinkedIn only.
• Reusing a 16:9 video everywhere. Vertical slots will crop it or surround it with empty space.

The takeaway

You do not need to memorise any of this. Keep the two tables nearby, shoot vertical by default, and let the checks catch the rest before a client does. If you want to run all ten networks from one calendar, you can request a Postilik account. Accounts currently open by request.