Every platform has character limits, and most people only find out when they've already written too much. Here's a reference guide to the limits that actually matter — and how to write efficiently within them.
Twitter / X
| Type | Limit |
|---|---|
| Tweet | 280 characters |
| Tweet with media | 280 characters |
| Display name | 50 characters |
| Bio | 160 characters |
| Username (@handle) | 15 characters |
Practical notes:
- URLs count as 23 characters regardless of actual length (Twitter wraps all URLs in t.co links)
- Hashtags and @mentions count as regular characters
- Replies: the @mention you're replying to doesn't count toward your 280
- Twitter Blue users get longer tweets (4,000+ characters) but standard is still 280
Strategy: Write your point in under 230 characters to leave room for a URL and a hashtag. If you need more, use a thread.
| Type | Limit |
|---|---|
| Post | 3,000 characters |
| Article | 125,000 characters |
| Bio / Summary | 2,600 characters |
| Job description | 25,000 characters |
| Headline | 220 characters |
| Comment | 1,250 characters |
Practical notes:
- LinkedIn posts expand with a "See more" link after about 210 characters. The hook before the cut-off is what drives click-through.
- The algorithm rewards engagement (comments > reactions > shares). Posts that prompt responses tend to be questions or strong opinions.
SEO meta tags
| Tag | Recommended range | Hard limit |
|---|---|---|
| Page title | 50–60 characters | ~600px pixel width (roughly 60 chars) |
| Meta description | 120–160 characters | ~920px (roughly 155 chars) |
| URL slug | 50–100 characters | No hard limit, but shorter ranks better |
Why the pixel measure? Google truncates titles and descriptions based on rendered pixel width, not character count. A word full of wide characters (M, W) gets cut off sooner than one with narrow characters (i, l, t).
Rules of thumb:
- Title tag: Keep under 60 characters. Front-load the keyword.
- Meta description: 140–155 characters is the sweet spot. Include a call to action.
- Titles that get truncated show as "My Article Title Name Here…" — the ellipsis appears if you go over. Always preview in a SERP simulator before publishing.
HTML attributes
| Attribute | Limit |
|---|---|
alt text |
No hard limit; under 125 characters recommended |
title attribute |
No hard limit; browsers truncate tooltip display |
href (URL) |
Up to ~2,048 characters for Internet Explorer; modern browsers allow more |
Email subject lines
| Platform | Displayed chars | Recommended |
|---|---|---|
| Gmail | ~60 desktop, 30 mobile | Under 50 |
| Apple Mail | ~60 | Under 50 |
| Outlook | ~70 | Under 50 |
Practical advice: Write subject lines under 50 characters to display fully on mobile. The preview text (preheader) that follows in inbox view is typically the first 80–90 characters of email body text — write your first sentence with that in mind.
SMS and text messages
| Type | Limit |
|---|---|
| Standard SMS | 160 characters |
| Long SMS (multi-part) | Up to 1,600 characters (10 × 160 segments) |
| Unicode SMS | 70 characters per segment (emoji or non-ASCII halves the per-segment limit) |
The emoji trap: One emoji converts an SMS from ASCII to Unicode encoding, dropping the per-segment limit from 160 to 70. A marketing SMS with 3 emojis could silently split into 3 billable message segments.
| Type | Limit |
|---|---|
| Caption | 2,200 characters |
| Bio | 150 characters |
| Username | 30 characters |
| Story text overlay | ~150–200 characters (visual, not enforced) |
Practical notes:
- Only the first 125 characters of a caption show before "More" — lead with the key message.
- Instagram hashtags count as characters. The 2,200 limit includes hashtags.
- Instagram bio: 150 characters is tight. Link-in-bio tools (Linktree etc.) expand this with a landing page.
YouTube
| Type | Limit |
|---|---|
| Title | 100 characters |
| Description | 5,000 characters |
| Tags | 500 characters total |
Practical notes:
- YouTube truncates titles at ~70 characters in search results. Put the keyword early.
- The first 125 characters of the description appear as a snippet in search results and suggested videos.
Domain names
| Element | Limit |
|---|---|
| Individual label (e.g., "example") | 63 characters |
| Full domain | 253 characters |
| TLD | 63 characters |
In practice, domain names longer than 20–30 characters are hard to type, share, and remember.
Keeping track in real time
When writing content that needs to stay within limits, a word and character counter that shows platform-specific limits is faster than counting manually. Paste your draft and see instantly whether it fits Twitter, a meta description, or an SMS segment.
A few things to remember across all platforms:
- Test on mobile. Character limits that look fine on desktop often truncate on phone screens.
- Front-load your message. When text is cut off, the first few sentences carry the full weight.
- Whitespace counts. Spaces, line breaks, and tabs are all characters.
- Emoji width varies. Emoji can take 1 or 2 characters depending on the emoji and the platform — complex emoji sequences (family emoji, flags) can take 5–10 code points.