---
title: What each platform accepts
description: Text limits, how many images and videos, PDFs and first comments, for every platform you can connect.
---

# What each platform accepts

Every platform has its own rules. Schedule & Chill checks your post against them **before** it is scheduled, so a post does not fail later.

## The rules for each platform

| Platform | Text limit | Images | Video | PDF | Needs media | First comment |
|---|---|---|---|---|---|---|
| LinkedIn | 3,000 characters | Up to 9 | 1 | 1 PDF, up to 300 pages and 100 MB | No | Yes |
| Bluesky | 300 characters | Up to 4 | No | No | No | No |
| Mastodon | 500 characters (your server may allow more) | Up to 4 | 1 | No | No | Yes |
| YouTube | 5,000 characters | No | 1 | No | Yes, a video | No |

No platform above accepts images and video in the same post. A PDF is always posted on its own.

## When you post to several platforms at once

- The composer lets you attach only as many files as the **strictest** selected platform allows.
- If your post breaks a rule on one platform, the composer shows a message for that channel, for example **Only 4 images per post — 6 attached.** Fix it, remove that channel, or give that channel its own caption. See [Different text for each channel](/help/posts/per-channel-text).

## How characters are counted

- **X:** every link counts as 23 characters and every emoji as 2.
- **Bluesky:** an emoji counts as 1 character, even complex ones.
- **Mastodon:** every link counts as a fixed number of characters set by your server, usually 23. Your server can also allow more text than the default.
- **All others:** every character counts as 1.

If a caption is too long, you see **The caption is … characters; the limit is ….**

## Messages you may see in the composer

| Message | What to do |
|---|---|
| **Needs at least one video.** | Add a video. |
| **Needs at least one image or video.** | Add an image or a video. |
| **Video isn't supported.** / **Images aren't supported.** | Remove that media, or post it to a different channel. |
| **Images and video can't share a post.** | Use only images or only a video. |
| **PDFs aren't supported.** | PDFs work on LinkedIn only. |
| **A PDF can't share a post with images or video.** | Post the PDF on its own. |
| **… is an audio file. Audio is stored in your library for editing, but it cannot be attached to a post.** | Audio can live in your library but cannot be posted. |