TikTok caption generator: describe the video, get up to five short captions.
StoriesFly's TikTok caption generator turns a 5 to 500 character description of your video into up to five caption drafts in the tone and language you pick, each asked to stay within 150 characters and cut by our server at 200, with up to five hashtags per draft, free for five runs a day and 50 on the Basic plan. The model reads only your text, never the video, and its knowledge ends in June 2024. TikTok itself documents a caption limit of 2,200 characters for posts made through its API.
5 runs a day free, 50 on Basic, no daily count on Pro · resets 00:00 UTC
What a draft is written froma description, 5–500 charactersone of 5 tonesWhat lands in the cardsup to 5 draftsnone over 200 characters
TikTok API caption: 2,200 characters5 free runs a day, 50 on Basicno login needed
The wall is ours, not TikTok'sTikTok documents 2,200 characters for captions posted through its API, eleven times this wall. The 200 is the server's own slice: a draft longer than that is cut there, possibly mid-word. The character count under each draft turns amber past 150, the length the model was asked to stay under.
What the prompt asks for, and what the server checks
The model is asked for more than the code verifies. Only the second route is guaranteed.
Instructions in the prompt. Nothing in the code checks them.
There is no refill: when a draft is dropped, the run returns fewer than five.
TikTok's API takes 2,200 characters. The drafts stop at 200.
TikTok documents its caption limit in its Content Posting API reference: the caption field holds at most 2,200 UTF-16 runes, hashtags and @mentions parsed from the same string. Captions typed in the app have been reported at 4,000 characters since 2023; that figure comes from third-party reports, not from TikTok's documentation.
The drafts here stay far below either figure. The prompt asks the model for 150 characters at most, and the server keeps no more than 200 of whatever comes back. The server counts the way JavaScript does, in UTF-16 units, so an emoji usually counts as two or more.
Short is a choice made in the prompt, not a TikTok rule. A draft works as the opening of a caption; anything longer, such as credits, a recipe or links, you add in TikTok after pasting.
The drafts come from gpt-oss-20b, whose knowledge ends in June 2024 according to OpenAI's model page. Slang, sounds and formats that caught on after that are unknown to it unless your description names them.
From a sentence to the draft cards
Beyond the fixed instructions, the model gets your description, a line about the tone and, for any language but English, a line about the language.
- 01Describe the videoBetween 5 and 500 characters. The model reads only this text, so name what happens on screen, where, and who it is for.
- 02Pick a tone and a languageCasual, professional, funny, thirst or educational; English, Spanish, Portuguese, Russian or Hindi. The drafts are written in that language, not translated from English.
- 03One request to the modelgpt-oss-20b, run by Groq, gets one prompt asking for exactly five drafts. There is no second pass and no trend data.
- 04The server trims and filtersEach draft is cut at 200 characters, drafts under 5 characters are dropped, and hashtags are reduced to a-z, 0-9 and _, five per draft at most. Dropped drafts are not replaced.
- 05Check the count, then copyEvery card shows its character count, which turns amber past 150. Copy puts the draft, a blank line and its hashtags on the clipboard as one block.
What one run is allowed
The same for every plan except the daily count. Tone and language are the only settings.
Your sentence is the whole input
The model never sees the video, so a draft can only be as specific as the sentence you type about it.
The request carries three fields: description, tone and language.
What the caption drafts cannot do
Worth a look before a draft goes live.
- 01Slang stops in June 2024The model's knowledge ends there and it gets no trend data, so this month's sounds, memes and phrases appear only if your description names them.
- 02A run can come back shortDrafts under 5 characters are dropped and nothing replaces them, so a run can return fewer than five, and in the worst case none. The run still counts toward the day's runs.
- 03A cut can land mid-wordA draft over 200 characters is sliced at character 200 with no attempt to finish the word. Read the ending before you post it.
- 04No moderation stepOnly the thirst tone carries a prompt line asking for PG-13, and no check runs on the output. Read drafts before they go on a brand account.
- 05Hashtags in Latin letters onlyA caption can be in Russian or Hindi, but its hashtags are cut to a-z, 0-9 and _, so tags in other scripts vanish.
- 06A daily count, per address or per accountWithout an account you get five runs per IP address per UTC day, counted apart from the hashtag generator and shared by everyone behind that address. Signed in, the count moves to your account and both generators draw on it: five a day on Free, 50 on Basic, and Pro runs are not counted. On a day the server's AI spending cap is reached, Free and signed-out runs pause until 00:00 UTC while Basic and Pro continue.
- 07No memory between runsEach run is a fresh request. The tool does not learn your voice or keep earlier drafts, so copy what you want before running again.
TikTok captions, the practical questions
What is the character limit for a TikTok caption?
2,200 characters for posts made through TikTok's Content Posting API; that is the figure TikTok documents. Captions typed in the app have been reported to allow 4,000 characters since 2023. Drafts from this tool stop at 200.
How many captions does one run give?
Up to five. The prompt asks for exactly five, but the server drops any draft under 5 characters and does not ask again, so a run can return fewer.
Why are the drafts so short?
Because the prompt asks for 150 characters at most and the server keeps no more than 200. Anything longer, such as credits or a list, you add in TikTok after pasting.
Can it write captions in other languages?
Yes: Spanish, Portuguese, Russian and Hindi as well as English. The model is told to write in that language rather than translate from English, but the hashtags stay in Latin letters, digits and underscores.
Does it look at my video?
No. The model gets only the text you type; there is no video upload and no link to your TikTok account, so describe what happens on screen.
Is the daily limit shared with the hashtag generator?
Only when you are signed in. Without an account each tool keeps its own five runs per IP address per UTC day. Signed in, both tools draw on one count on your account: five a day on Free, 50 on Basic, and Pro runs are not counted. Counts reset at 00:00 UTC.
Do you keep my description?
No. It is sent to Groq, which runs the model, and StoriesFly does not store it; when a run fails, the error log records only the tone and the language.
More Free Tools
The same job on Instagram: Caption Generator
Describe the video in a sentence, and up to five drafts come back with their lengths.
Free for five runs a day; Basic raises it to 50.