Character Limits on Every Major Platform: A Reference

Every field has a ceiling, and hitting it after you have written the copy is the worst time to find out. This is a reference for the limits that are long-standing and widely documented, with honest notes where the behaviour is more complicated than a number.

Verify before you commit. Platforms change these limits, often quietly and often only for some accounts, subscription tiers, or regions. Treat everything below as a starting point and check the platform's own help documentation or developer docs before you build a workflow around a figure. Where a limit is genuinely unstable or tier-dependent, this article describes the behaviour instead of quoting a number.

The table

Platform / field	Limit	Notes
X (Twitter) post	280 characters	The standard limit since 2017. Paid subscription tiers allow far longer posts; the 280 figure is what unpaid accounts and most API contexts assume.
X display name	50 characters	Handle is separate and shorter.
Instagram caption	2,200 characters	Truncated in feed after roughly the first line or two with a "more" link.
Instagram bio	150 characters	Line breaks count.
Instagram comment	2,200 characters	Same ceiling as captions.
Instagram hashtags	30 per post	A count limit, not a character limit.
WhatsApp message	65,536 characters	Enormous in practice; you will hit readability limits long first.
WhatsApp About	139 characters	The short profile line.
WhatsApp text status	Several hundred characters	Around 700 is commonly cited, but the font shrinks as you type and it becomes unreadable well before the cap.
Discord message	2,000 characters	4,000 for Nitro subscribers. Long-standing and stable.
Discord username	32 characters	Minimum 2.
Telegram message	4,096 characters	Longer pasted text is offered as a file or split.
Telegram media caption	1,024 characters	Notably shorter than a plain message.
Telegram bio	70 characters	Longer for premium accounts.
TikTok caption	2,200 characters	Historically 150; expanded substantially. Verify — this one has moved more than most.
Facebook post	63,206 characters	A famously large and long-stable figure. Feed truncates with "See more" far earlier.
Facebook comment	8,000 characters
LinkedIn post	3,000 characters	Truncated in feed after roughly 200 characters with a "see more" link.
LinkedIn comment	1,250 characters
LinkedIn headline	220 characters	Was 120 for years; check yours, as older accounts have reported inconsistent behaviour.
SMS, single segment	160 characters (GSM-7)	70 characters if any Unicode character is present. See below.
SMS, multi-segment	153 characters per segment (GSM-7)	67 per segment for Unicode.
Email subject line	No hard protocol limit	Display is what constrains you. See below.
HTML <title>	No hard limit	Search results truncate by pixel width, not character count. See below.
Meta description	No hard limit	Same pixel-width truncation. Roughly 155–160 characters is the working guideline.

Run your draft through the character counter against whichever row applies before you paste it anywhere.

The rows that need more than a number

SMS is counted in segments, not characters

SMS is the most misunderstood entry in the table because the limit is not really about characters at all.

A standard SMS carries 140 bytes. Using the GSM-7 character set, each character packs into 7 bits, giving you 160 characters. That is where the famous number comes from.

Two things break it:

1. Any character outside GSM-7 — most emoji, curly quotes, em dashes, accented characters not in the basic set, and any non-Latin script — forces the whole message into UCS-2 encoding at 16 bits per character. Your limit drops to 70 characters for the entire message, not just for the special character. A single curly apostrophe pasted from a word processor can more than halve your capacity.
2. Going over one segment costs you space in every segment. Concatenated SMS reserves part of each segment for header information that tells the receiving phone how to reassemble the parts. That leaves 153 characters per segment in GSM-7, or 67 in UCS-2.

So a 200-character GSM-7 message is two segments (and two segments' worth of cost, if you are paying per message), not one and a bit. And note that a few GSM-7 characters — including {, }, [, ], \, |, ^, ~ and the euro sign — occupy two character slots each because they are encoded as an escape sequence.

If you are writing bulk SMS, the practical advice is: use straight quotes, avoid emoji unless you have budgeted for UCS-2, and count before you send.

Email subject lines are limited by display, not by protocol

There is no meaningful hard cap. Mail clients and the standards behind them tolerate very long subject lines. What constrains you is how much gets shown in an inbox list.

Roughly:

• Desktop webmail clients typically show somewhere around 60 characters before truncating.
• Mobile clients show considerably less, often in the range of 30 to 40 characters depending on device width and font size.
• Some clients append or prepend text of their own, eating into the space.

The practical rule is to put the information that matters in the first 30 to 40 characters and treat everything after that as a bonus that some readers will see. Do not write a subject line where the meaning only becomes clear at character 70.

Title tags and meta descriptions are measured in pixels

Search engines truncate result snippets by rendered width, not character count. A title made of capital letters and wide characters truncates sooner than one made of narrow lowercase letters, at the identical character count.

The commonly used working guidelines are around 50 to 60 characters for a title and around 155 characters for a description, and those are fine as guidelines. But treat them as approximations of a pixel budget, and understand that the search engine may rewrite your title or generate its own description from page content regardless of what you wrote. Write something that reads well truncated, and put the distinguishing words first.

Working within the limits

A few habits that save time:

Write to the truncation point, not the limit. Instagram allows 2,200 characters but shows one or two lines before "more". LinkedIn allows 3,000 but shows around 200. The number that matters for whether anyone reads you is the truncation point, not the cap.

Count before you paste, not after. Pasting into a live field and watching it cut off risks posting a half-finished message. Check the length first.

Split deliberately. When your text genuinely exceeds a limit, the message splitter cuts at sensible boundaries rather than mid-word, which is what happens if you leave it to the platform.

Watch what invisible and stylised characters cost you. Blank padding characters count against the limit exactly like visible ones. Stylised Unicode from a fancy text generator frequently costs more than one character per glyph, and on SMS it will push you into UCS-2 immediately.

Test the field, do not trust the label. If you are building something, generate an over-length string with the text repeater and paste it in. You will find out quickly whether the field truncates silently, rejects with a useful error, or fails in a way that loses the user's work. Platform-specific repeaters like the Instagram one default to the relevant ceiling, which makes this faster.

Everything referenced here lives in the full tool list.

Key takeaways

• Verify current limits against each platform's own documentation before relying on them; subscription tiers and quiet changes make any published table a snapshot.
• SMS is counted in segments: 160 GSM-7 characters for one message, 153 per segment when concatenated, and 70 or 67 the moment any Unicode character appears.
• Email subjects, title tags and meta descriptions have no hard cap — they are constrained by display width, so front-load the meaning.
• The truncation point where a feed shows "see more" matters more for readership than the actual character ceiling.