Every social media platform, ad network, and messaging service has character limits. Going over means your text gets cut off. Here’s a complete reference for every platform that matters.
Social media character limits
| Platform | Field | Limit |
|---|---|---|
| Twitter/X | Tweet | 280 characters |
| Twitter/X | Bio | 160 characters |
| Twitter/X | Display name | 50 characters |
| Caption | 2,200 characters | |
| Bio | 150 characters | |
| Hashtag | 30 per post | |
| Post | 63,206 characters | |
| Ad headline | 40 characters | |
| Ad description | 125 characters | |
| Post | 3,000 characters | |
| Article title | 100 characters | |
| Headline (profile) | 220 characters | |
| TikTok | Caption | 2,200 characters |
| YouTube | Title | 100 characters |
| YouTube | Description | 5,000 characters |
| Pin description | 500 characters |
SEO character limits
| Field | Recommended limit |
|---|---|
| Page title | 50-60 characters |
| Meta description | 150-160 characters |
| URL slug | Under 75 characters |
| H1 heading | Under 70 characters |
| Image alt text | Under 125 characters |
Google truncates titles around 60 characters and descriptions around 160 characters in search results. Staying within these limits ensures your text displays fully.
Messaging limits
| Platform | Limit |
|---|---|
| SMS | 160 characters (standard) |
| SMS (Unicode) | 70 characters |
| iMessage | No hard limit |
| 65,536 characters | |
| Slack message | 40,000 characters |
| Discord message | 2,000 characters |
| Telegram | 4,096 characters |
SMS encoding matters
Standard SMS uses GSM-7 encoding: 160 characters. But if you use any character outside the basic set (emoji, accented characters, Chinese/Japanese/Korean), it switches to Unicode (UCS-2) and the limit drops to 70 characters.
A single emoji can halve your SMS character budget.
Characters vs bytes
Some systems count bytes, not characters:
- ASCII characters: 1 byte each
- Accented characters (é, ñ): 2 bytes in UTF-8
- Emoji: 4 bytes in UTF-8
- Some emoji (flags, skin tones): 8-28 bytes
This matters for database columns, URL lengths, and API payloads.
Writing within limits
For tweets (280 chars)
- Lead with the key point
- Cut filler words (“very”, “really”, “just”)
- Use abbreviations when clear
- Thread long thoughts into multiple tweets
For meta descriptions (160 chars)
- Include the primary keyword
- Add a call to action
- State the benefit clearly
- Don’t stuff keywords — write for humans
For ad copy (25-40 chars)
- Every word must earn its place
- Use numbers (“Save 30%“)
- Action verbs (“Get”, “Try”, “Start”)
- Test variations
A character counter that shows counts in real time helps you stay within limits while writing — no need to guess or count manually.