Caption length checker
Paste your caption and see its fate on ten platforms at once. X caps at 280 characters and Bluesky at 300 — a hard rejection, not a trim — while TikTok and Instagram allow 2,200 and LinkedIn 3,000. The checker counts what you pasted against each limit and shows exactly how far over you are.
Given a caption you paste, produce its fate on every platform at once, in under one second.
184 characters
| X | 280 | fits |
| Bluesky | 300 | fits |
| 500 | fits | |
| Threads | 500 | fits |
| Discord | 2,000 | fits |
| TikTok | 2,200 | fits |
| 2,200 | fits | |
| 3,000 | fits | |
| YouTube description | 5,000 | fits |
| 63,206 | fits |
Limits checked 2026-09-04.
You know which platforms reject this one caption. You still have to write a different one for each of them, every time you post — the shortening is the easy half.
Next artifact: a caption per platform, already written to fit.
Never writes the per-platform variants from the video's own transcript and shortens the long ones by cutting the tail, not the hook, before anything is scheduled.
See how the posts get writtenYour caption is counted in your browser. It is never sent anywhere, never stored, and there is nothing to delete.
Why caption character limits still bite in 2026
Caption limits still bite because cross-posting is the norm and the limits differ by an order of magnitude. A caption born on TikTok, where 2,200 characters are available, is rejected outright by X at 280 and Bluesky at 300. The failure happens at publish time, after the video is already rendered and scheduled.
The mismatch is worst for the platforms that matter most to a small audience. Bluesky and X are where a written hook does the most work, and they are the two with the tightest limits, so the caption that reads best is usually the one that fails. The caption length checker makes the mismatch visible before you queue the post rather than after the queue rejects it.
How to check caption lengths by hand
- Write the long one first. Draft against the most generous limit — 2,200 characters on TikTok or Instagram — because it is easier to cut a caption down than to pad one out.
- Count, do not estimate. Paste into any character counter. Word processors count words; platforms count characters, and emoji do not count as one.
- Cut the tail, never the hook. The first line is what decides whether the rest is read. When a limit forces a cut, take it from the end.
- Re-check after every edit. A single added emoji can put a 279-character post over 280.
Where the manual way breaks
One caption against ten limits is a minute of work. A week of posting is not: one recording that produces eight clips and a long-form, published to five platforms, is 45 captions — and the Editing Tax dataset puts writing hooks and per-platform copy at 40 minutes for a single recording's set, before any of them is counted or shortened.
The deeper problem is that shortening is the easy half. The hard half is that each platform rewards different phrasing, so a correctly-shortened caption can still be the wrong caption. Never writes the per-platform variants from the video's own transcript and shortens by cutting the tail rather than the hook, then schedules them against the calendar — which is where a rejected 301-character post would otherwise surface, silently, hours later.
Read the transcript
Caption length checker Paste your caption and see its fate on ten platforms at once. X caps at 280 characters and Bluesky at 300 — a hard rejection, not a trim — while TikTok and Instagram allow 2,200 and LinkedIn 3,000. The checker counts what you pasted against each limit and shows exactly how far over you are.
Frequently asked questions
Which platform rejects captions most often?
Bluesky, in practice. 300 characters is a hard limit and most cross-posted captions were written against TikTok's 2,200, so the same text that publishes everywhere else fails there. Reposting without checking is the most common avoidable publish failure.
Should the same caption go to every platform?
The substance, yes. The wording, no. Each platform rewards different phrasing and different length, and a caption written for X wastes the room TikTok gives you to set up a hook. Never writes per-platform variants automatically before anything is scheduled.
Do emoji and links count against the limits?
Platforms count them differently — some count every URL at a fixed length regardless of the real one, and an emoji can count as two characters or more. The caption length checker counts Unicode characters the way platforms broadly do; within 5% of a limit, shorten anyway.