Caption length checker

How it works

Characters. The tool counts characters the way you see them, line breaks and spaces included, so an emoji with a skin tone or a flag counts as one. TikTok’s Content Posting API documents its limits in UTF-16 runes, where many emoji take two or more. If your text fits by character count but not by UTF-16 units, the tool shows a warning on the two TikTok rows, and in that case it is worth shortening to be safe. Meta documents no such unit for Instagram, so the Instagram rows carry no UTF-16 warning.

Hashtags and mentions. A hashtag is a # followed by letters, numbers or underscores, at the start of the text or after a space or punctuation, with at least one letter in it. So “#1” in “tip #1” is not counted. Numbers-only tags are never counted, which may undercount if an app treats them as tags. Tags written without a space, such as “#one#two”, count as two. A mention is an @ followed by a handle, and an e-mail address is not one. The apps’ own parsers may differ at the edges.

Where the limits come from (as of November 2026):

• TikTok caption, 4,000 characters: TikTok’s Creator Academy says up to 4,000, and the Content Posting API gives 4,000 UTF-16 runes. Some guides and tools still show 2,200, which was TikTok’s 2022 figure.
• TikTok title, 90: the Content Posting API limits the title to 90 UTF-16 runes. The app may present the field differently, so treat 90 as the safe upper bound.
• Instagram caption, 2,200: the Instagram Graph API reference gives 2,200 as the maximum. That comes from developer documentation, and we did not find it in Instagram’s Help Center, so check the app if you are close.
• Instagram hashtags, 5: the Help Center says up to five. The rollout was gradual, so some accounts may still see a higher limit, and the developer docs still mention 30.

How to use the result

A limit is a ceiling, not a target. Use the room only if the words earn it. Write the first line so it stands on its own, and put the longer part after it.

For a TikTok photo post, the Creator Academy says the title counts, and advises a title that works as a hook. Write the title first and keep it well under 90 characters. Then use the caption for context, credit and the things the slides had no room for. The TikTok slideshow captions guide goes deeper.

On Instagram, count your hashtags before you post. TikTok has reportedly shown some users a five-hashtag notice, but TikTok has not confirmed a rule, so this tool shows the TikTok hashtag count without judging it.

If you reuse one caption on both platforms, check it against both sets of limits. A caption that fits TikTok’s 4,000 characters can be well over Instagram’s 2,200, and the hashtag habits of the two apps differ as well, so trim the copy for each platform instead of pasting it unchanged.

Limits change. If a number here disagrees with what the app shows you, trust the app. Nothing in this tool predicts reach or views; it only counts. Check slide text separately with the slide text checker.