Platform limits: captions, titles, covers, video
Caption and title limits for all eleven platforms, which ones take a custom video cover, and the video ceiling that applies everywhere. Read from the product config.
Eleven platforms, eleven sets of limits. The composer enforces these as you type, so you find out before a post is scheduled rather than after it fails. The numbers below are read straight from the same configuration the publisher uses.
Caption and title limits
| Platform | Caption limit | Title limit |
|---|---|---|
| 2,200 characters | — | |
| 63,206 characters | — | |
| TikTok | 2,200 characters | — |
| YouTube | 5,000 characters | 100 characters |
| 3,000 characters | — | |
| X | 280 characters | — |
| 800 characters | 100 characters | |
| Threads | 500 characters | — |
| Bluesky | 300 characters | — |
| Mastodon | 500 characters | — |
| Telegram | 4,096 characters (1,024 with media) | — |
Mastodon's limit belongs to your server
The limit counts your hashtags too
Titles exist on YouTube and Pinterest only. On the rest, the caption is the whole post. In a CSV import, the title column feeds exactly those two.
Video, everywhere
| Limit | Value |
|---|---|
| Maximum file size | 200 MB |
| Maximum duration | 15 minutes |
These apply on every platform, not per platform. Anything over them is stopped before it enters the queue rather than failing at publish time. Video uploads run in the background over a resumable connection, so a large file does not lock the composer.
Individual platforms may be stricter about what they accept for a given post type — a Reel and a long-form upload are not the same thing to Instagram. If a platform rejects a file it took here, the reason lands on the post; see why a post failed.
Post types, covers and alt text
| Platform | Post types | Video cover | Alt text |
|---|---|---|---|
| Reel, feed post, carousel, Story | Upload one, or pick a frame | — | |
| Text, image, video, Reel, link, carousel | Upload one | — | |
| TikTok | Video, photo post | Pick a frame | — |
| YouTube | Video (Shorts by format) | Upload one | — |
| Text, image, video, link, article, poll, document | Upload one | Yes, on images | |
| X | Text, image, video | Set by the platform | — |
| Image and video pins | Upload one, or pick a frame | Yes | |
| Threads | Text, image, video, carousel | Set by the platform | — |
| Bluesky | Text, image, video | Set by the platform | Yes, on images |
| Mastodon | Text, image, video, poll | Set by the platform | Yes, on images |
| Telegram | Text, photo, video, album | Set by the platform | — |
Reading the cover column
- Upload one — attach your own image as the cover or thumbnail.
- Pick a frame — scrub the video and choose the frame to freeze on.
- Set by the platform — X, Threads, Bluesky, Mastodon and Telegram generate the still themselves, and their APIs accept no alternative.
Pinterest video pins require a cover, so one is always set. Everywhere else it is optional and falls back to the platform default.
Images
Instagram is the one platform with an aspect-ratio rule: images must sit between 0.8 and 1.91 — roughly 4:5 portrait through 1.91:1 landscape. Schedchie warns in the composer and pads out-of-ratio images automatically (blurred edges, never cropped) so the post still publishes — only on Instagram; other platforms get the untouched file.
Alt text is offered on LinkedIn, Pinterest, Bluesky and Mastodon, which are the platforms whose APIs accept it on a scheduled post.
What each platform can do beyond the numbers — the settings, the extras, the connection details — is on its own page: Instagram, Facebook, TikTok, YouTube, LinkedIn, X, Pinterest, Threads, Bluesky, Mastodon, Telegram.
Related help
Publishing
Bulk import from CSV
The column spec (datetime, text, media, title), how filenames match uploaded files, the per-platform picks, and what the validator checks before anything is created.
Publishing
Why a post failed
Read per-account publish results, tell Partial from Failed, retry only the accounts that missed, and match the common platform errors to their fix.
Start here
Getting started
The first four steps in Schedchie: connect an account through the platform, write one post for all of them, put it on the calendar, and check what went out.
Not covered here?
Write to support@schedchie.com with the account name and the scheduled time of the post, and you get a person, not a form.
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