Say it in the first sentence
People meet a TikTok with the video already playing. The caption is the line beside it. The first sentence should name what the video shows, because a lot of viewers will not open the rest. On-screen text is a separate layer. Write that for someone watching with the sound off, and write the caption so it still makes sense if they never read the on-screen text.
The caption generator uses the subject you type as that first sentence. Add one detail you can point at in the video. Leave the detail blank if you do not have one yet.
Hashtags share the caption limit
TikTok's Content Posting API documents a video caption maximum of 2,200 UTF-16 code units. Hashtags and mentions are part of that text. TikTok publishes no separate maximum number of hashtags. Any count you see quoted as TikTok's rule is someone else's recommendation.
A photo post uses a different description field in that API, with a higher documented length. When you post photos, trust the counter in the app. The generator's TikTok check is the video-caption figure, and it says so on the result.
Rewrite a caption you are moving from another app
The same clip can be posted in more than one place if you have the right to post it. The caption usually cannot. An Instagram caption that leans on a carousel, or a YouTube description that leans on chapters, reads as imported when it lands on TikTok. State the video in one sentence and keep the tags that name this clip. The bio is a different field from this caption. Draft it with the bio generator, then read how to write a TikTok bio.
The posting grid is a starting hour you then replace with your own view counts. It does not write the caption, and it does not post for you.
Use your own view count afterward
A caption check tells you the line fits. It does not tell you the video was watched. The engagement rate calculator divides likes, comments, shares, and saves by the views you paste in. That percent is not average watch time.
Paid plans stay on YouTube: Pro is $9 a month, Growth is $19, and Unlimited is $39. They do not publish TikToks. The caption tool stays free.
Questions
How long can a TikTok caption be?
TikTok's Content Posting API caps a video caption at 2,200 UTF-16 code units. Photo posts use a different field. Confirm the counter in the app when you post.
How many hashtags does TikTok allow?
TikTok does not publish a hashtag count. Tags share the caption's character limit. Use a few that name the video.
Should I paste my Instagram caption onto TikTok?
Only after you rewrite the first sentence for someone who did not see the Instagram post. Keep the tags that still name this clip.