Social Media Character Limits

Official limits for posts, captions, bios and usernames on every major platform, each linked to its source.

Researched by NameSniper ResearchVerified October 2026We verify platform rules against official sources and re-check regularly.
PlatformMax lengthAllowed characters
Bluesky253letters, numbers, hyphens (-) - case-insensitive (stored lowercase). Short form like "alice" (auto-appends .bsky.social) or full DNS like "alice.bsky.social"
GitHub39letters, numbers, hyphens (-) - no leading, trailing, or consecutive hyphens
Instagram30letters, numbers, periods (.), underscores (_) - no consecutive periods, cannot start or end with a period
Kick25letters, numbers, and underscores (_)
LinkedInRules only, not checked100letters, numbers, hyphens (-)
Linktree50letters, numbers, periods (.), underscores (_), hyphens (-)
npm214lowercase letters, numbers and hyphens (-)
Pinterest30letters, numbers, underscores (_) - must include at least one letter
RedditChecking paused20letters, numbers, underscores (_), hyphens (-)
Roblox20letters, numbers, at most one underscore (_) - not as the first or last character
Snapchat15letters, numbers and one hyphen (-), underscore (_) or period (.) - must start with a letter and end with a letter or digit
SubstackChecking paused32letters and numbers only
Telegram32letters, numbers, underscores (_) - must start with a letter, no consecutive or trailing underscores
Threads30letters, numbers, periods (.), underscores (_) - no consecutive periods, cannot start or end with a period
TikTok24letters, numbers, underscores (_) and periods (.) - cannot end with a period
Twitch25letters, numbers, underscores (_)
X (Twitter)15letters, numbers, and underscores (_) only
YouTube30letters and numbers in any of YouTube's 75 supported languages, underscores (_), hyphens (-), periods (.), middle dot (·) - cannot start or end with a separator

Post, caption and bio limits by platform

Limits for what you write, taken from each platform’s own help center or developer docs. Where the only official figure comes from a developer API, the row says so. Where a platform doesn’t publish a limit at all, it isn’t listed.

Official limits, verified 2026-10-01

Post, caption and bio character limits by platform
FieldLimit
Bluesky
PostSource Counted in graphemes (what you see as one character)300
Display nameSource Counted in graphemes64
BioSource Counted in graphemes256
GitHub
BioSource 160
Instagram
CaptionSource From Meta's developer docs2,200
Hashtags per postSource Meta's API docs still say 305
BioSource 150
LinkedInRules only, not checked
PostSource 3,000
Pinterest
Pin titleSource 100
Pin descriptionSource Organic Pins; ad specs differ800
BioSource 500
Snapchat
Display nameSource Including spaces30
Telegram
MessageSource 4,096
Media captionSource 4,096 with Telegram Premium1,024
BioSource 140 with Telegram Premium70
Threads
PostSource Longer text continues in a new thread automatically500
TikTok
CaptionSource Set by TikTok's posting API; TikTok's help center publishes no caption limit for the app2,200
NicknameSource Can be changed once every 7 days30
Twitch
BioSource 300
X (Twitter)
PostSource 25,000 with any X Premium tier280
BioSource 160
YouTube
Video titleSource 100
Video descriptionSource 5,000
Channel descriptionSource 1,000

Why character limits matter

Every platform caps usernames, display names and bios, and most cap posts and captions too. Go over a profile limit and the form won’t save. Plan a handle that fits all the platforms you want to be on and you won’t have to pick different names later.

The 15-character rule

Snapchat and X (Twitter) cap usernames at 15 characters, the tightest maximum on any platform we check, while Telegram and X (Twitter) require at least 5. A handle of 5-15 characters clears the length rules everywhere we check.

Strictest username limits to design around

If you want one consistent handle everywhere, design against the tightest maximums:

  • 15 characters - Snapchat and X (Twitter)
  • 20 characters - Roblox
  • 24 characters - TikTok
  • 25 characters - Kick and Twitch
  • 30 characters - Instagram, Pinterest, Threads, and YouTube

Bio and display name limits vary more widely, but usernames are the hard constraint - the handle is what appears in URLs, mentions, and DMs across every platform.

How to read the username table

The table at the top filters live. Switch between Username, Display name, and Bio tabs to see each platform’s max length for that field. The “Allowed characters” column summarizes format rules for usernames. Rows for platforms we don’t currently check are labelled.

Verification & sources

Each row in the post, caption and bio table links the official page it comes from, and the full list is below. Username rules come from each platform’s own pages too; where a platform doesn’t publish them (Instagram is the big one), we use what its sign-up form enforces and say so.

Sources & References

The official pages behind the limits on this page:

Frequently Asked Questions

What is the character limit on X (Twitter)?

A post can be 280 characters (25,000 with any X Premium tier). Your bio holds 160. Usernames are capped at 15 characters, and new ones need at least 5.

How long can an Instagram caption be, and how many hashtags can I use?

Captions can be up to 2,200 characters. Instagram's help center now allows up to 5 hashtags per post, and text with more than that won't post. Meta's API docs still say 30, so plan around the lower number.

What is the maximum username length on Instagram?

Instagram usernames can be up to 30 characters: letters, numbers, periods and underscores, with no period at the start or end and never two periods in a row. Instagram's help center doesn't publish these rules; they are what Instagram's own sign-up form enforces. The bio limit, which Instagram does publish, is 150 characters.

How long can a TikTok caption be?

TikTok's help center doesn't publish a caption limit. Its posting API caps video captions at 2,200 characters, which is the figure we list. Usernames run 2-24 characters, and the nickname shown on your profile can be up to 30.

Do emoji count as one character?

It depends on how the platform counts. Bluesky counts graphemes, so anything that displays as one character counts as one. TikTok's posting API counts captions in UTF-16 code units, where many emoji take two. Most platforms don't publish how they count, so leave some headroom when a post uses a lot of emoji.

Do these limits change?

Yes, and without much notice: Instagram has lowered its hashtag allowance, and Meta's own API docs still show the old number. That is why every row links the official page it comes from and the table shows the date we last checked. Where a platform doesn't publish a limit (Twitch stream titles, for example), we leave it out instead of quoting a guess.

What is the difference between a username and a display name?

Your username (handle) is the unique @identifier used in your profile URL and in mentions, so it can't contain spaces and most symbols. Your display name is the readable name shown on your profile. It can contain spaces, and on some platforms it doesn't have to be unique: Snapchat and Roblox display names, for example.

How do I check if my username fits everywhere?

Test it in the Username Length Checker and the Username Format Validator, which compare it against each platform's length and character rules. Then run a full NameSniper check to see where it is actually free.

Check All Platforms at Once

Don't check one platform at a time. NameSniper checks domains and social handles in a single search, with optional USPTO trademark screening.

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