What are the character limits on each social network?

Short answer

From each network’s own pages, read on 10 October 2026: X 280 (weighted), Bluesky 300, Threads 500, Instagram 2,200 and TikTok 2,200 through their APIs, LinkedIn 3,000, YouTube 100 for a title and 5,000 for a description, Pinterest 100 for a title and 800 for a description. Facebook publishes no figure for a post. For a bio: Instagram 150, X 160, Pinterest 500 and TikTok 80; LinkedIn, Threads, Bluesky and Facebook give none on the pages we read.

Written by the Mellow team · Updated October 10, 2026, sources read October 10, 2026

The limits, network by network

Network	Post or caption	Title, where there is one	Bio	Mellow Hub checks
Instagram	2,200 through the API; the Help Center gives no caption figure. Up to 5 hashtags	—	150 characters	2,200
TikTok	No figure in the Help Center. API: 2,200 for a video’s caption, 4,000 for a photo post’s description	Photo post, 90 (API)	80 characters	2,200; title 90
YouTube	Description 5,000 characters (Help), 5000 bytes (API)	100	Channel description 1000 (API)	5,000; title 100, required
X	280, weighted; up to 25,000 with X Premium	—	160 characters	280, weighted
LinkedIn	3,000 characters	—	No figure	3,000, required
Threads	500; up to 5 links	—	No figure	500
Bluesky	300 graphemes	—	No figure	300, required
Pinterest	Description 800 characters	100	500 characters	Description 500; title 100
Facebook	No figure	—	No figure	63,206

Where a source is not a link here, it is in the list at the end: Instagram’s API reference, TikTok’s Direct Post and photo post references, YouTube Help, X’s counting rules and Premium page, LinkedIn’s post page, Threads’ post reference, Bluesky’s documentation and Pinterest’s Pin specs. Bios come from Instagram, TikTok, X and Pinterest.

Where a network publishes no figure

Facebook: no limit for a post, a comment or a Page name on the pages we read. The Facebook page lists them.
TikTok in the app: the Help Center gives no caption figure; the numbers above are the API’s. The TikTok page has the detail.
LinkedIn headline and About: the help pages for the headline and the About section state no limit.
Threads and Bluesky bios: Instagram’s help for the Threads profile and Bluesky’s profile documentation state none.
Instagram captions in the Help Center: only the API reference gives 2,200.

Figures for these circulate widely. We don’t repeat them because no page of the network’s states them.

How each network counts

X weighs characters: a link counts 23 however long it is, an emoji or a Chinese, Japanese or Korean character counts 2, and most other characters count 1.
Threads counts an emoji as the number of bytes it takes in UTF-8, so a pointing hand is 4.
Bluesky counts graphemes: an emoji counts once, however it is built.
YouTube states a description in characters in its Help Center and in bytes in its API reference.
TikTok states its API limit in UTF-16 runes.

One caption, nine networks

Take a plain-text caption of 320 characters. It fits Instagram (2,200), TikTok (2,200), LinkedIn (3,000), Threads (500), Facebook, a YouTube description (5,000) and a Pinterest description (800). It is over on X (280) and on Bluesky (300).

Now take 280 letters and one pointing-hand emoji. X weighs the emoji 2, so it comes to 282: over. Bluesky counts 281: fine. Threads counts the emoji as 4, so 284 of 500: fine. The shortest limit decides, and it is X’s.

The free character counter counts a post against every network at once, with these rules.

With Mellow Hub

Hub holds a caption to each network’s limit before it sends, and the last column is what it checks. Where a limit differs from the network’s own number (Pinterest’s description, for one, is checked at 500), the registry’s is the stricter or the only one published. A caption over a network’s limit is cut at the last paragraph, line or sentence that fits, and the post’s notes say so; give a network its own caption when you want to choose the words. The free post checker runs the same checks on titles and media counts.

Hub is paid: plans start at $19 a month (Solo), after a 7-day trial with a card on file that costs nothing if you cancel before it ends, and a monthly plan's first month is 20% off. Publishing is unlimited on every plan, under a fair-use ceiling that stops automated floods (900 publications a month on Solo). One publication is one post on one account, so a post sent to five networks counts as five. There are no automatic overage charges.

Questions people also ask

Which social network has the shortest character limit?

X, at 280 weighted characters for most accounts, and then Bluesky at 300. A caption that fits both is inside every other caption limit in the table.

Which social network has the longest limit?

Of the figures networks publish, X Premium allows posts of up to 25,000 characters and YouTube a description of 5,000. LinkedIn’s limit for a post is 3,000. Facebook publishes no figure.

What is the character limit for a bio?

Instagram 150, X 160, Pinterest 500 and TikTok 80, according to each network’s own help. LinkedIn, Threads, Bluesky and Facebook state none on the pages we read.

Why does the same caption fit one network and not another?

Because they count differently. X gives a link a weight of 23 and an emoji 2, Threads counts an emoji as its UTF-8 bytes, and Bluesky counts what you see. YouTube states one of its limits in bytes.

Do hashtags count toward the limit?

Yes: a hashtag is text in the caption, so its letters count on every network in the table. Instagram also caps the number of hashtags in a post at 5.

Sources

Other companies’ features change. Every statement about them rests on these pages, as they read on the date above.