Free caption generator for Instagram, TikTok and LinkedIn
Describe your post and pick a network and a tone to get captions that fit its character limit. Free, in your browser, no sign-up, written by AI.
By Mellow · UpdatedCaption generator
Example (written by hand, not by the generator)
Doors open at 8. The first croissants are already out of the oven, and the coffee is on. Come and say hello.
New bakery on Calle Mayor, open from this morning. Bread, pastries and coffee, baked a few steps from where you are standing.
The limits it counts against
| Network | Limit | Where it comes from |
|---|---|---|
| 2,200 through the API; the Help Center gives no figure. Up to 5 hashtags | Meta for Developers: Instagram Graph API, IG User media read 1 October 2026 | |
| TikTok | 2,200 through the API; TikTok’s help gives no figure for the app | TikTok for Developers: Content Posting API, Direct Post read 1 October 2026 |
| Threads | 500, with an emoji counted as its UTF-8 bytes; no more than 5 links | Meta for Developers: Threads posts read 1 October 2026 |
| 3,000 | LinkedIn Help: post character limit read 1 October 2026 | |
| Description 800, title 100 | Pinterest Help: Review Pin specs read 1 October 2026 | |
| Bluesky | 300 graphemes (Unicode grapheme clusters) | Bluesky documentation: intent links, on post length read 1 October 2026 |
| Meta publishes no figure; 63,206 is the number reported elsewhere, and the one Hub checks | The network publishes no figure; the number Hub checks is on the networks page. |
Each figure is the network’s own, from its help or developer pages. The count under a result is on the network’s own scale, not a plain character count where the two differ.
What this generator does, and what it does not
- It writes options, not promises. It is told to promise no result, to state no figure about reach or popularity, and to invent no fact about you. An option that does is dropped.
- It does not post. Nothing here connects to an account. You copy a result and publish it yourself, or schedule it in Hub.
- It does not know you. It sees only what you type. Add the detail that is true of you; the details are what a reader keeps.
- It is free and needs no account. Each browser has a small daily allowance, shown above the results. The counters and checkers on the other free tools have no allowance: they run in your browser.
Questions
What is the character limit for a caption?
It differs by network, and the table above lists each one from the network’s own page with the day it was read. The number under each generated caption is counted the way that network counts, so an emoji or a link is not a surprise.
Should every network get the same caption?
Not usually. A shorter network needs a shorter text, and a text written for one audience reads oddly on another. Generate for each network and read each result as the person you want to reach.
Can it write in another language?
Yes. Describe the post in the language you want back, and the options come back in it. Check the result with a speaker of the language before you post it.
Why do I sometimes get fewer than five options?
An option a network would not accept, or one that promises results, is dropped rather than trimmed to fit. A page that shows two options is showing the two that passed.
Is the text written by AI, and is anything I type kept?
Yes, it is written by an AI model, so read it before you post and change what is not true of you. Your description is sent to the model to write the options. Mellow keeps no account for this tool; it keeps a one-way hash of the question with the answer for seven days so the same question is not paid for twice. Each browser has a small daily allowance, shown on the page.
Schedule what you write in Mellow Hub
Copy a result, then schedule it with the rest of your posts. Mellow Hub publishes one post to Instagram, TikTok, YouTube, X, LinkedIn, Threads, Bluesky, Pinterest and Facebook and checks each network’s rules before anything is sent.
Schedule on Instagram and TikTokRead every network’s character limit
This tool is free and needs no account. Mellow Hub is paid, after a 7-day free trial, and publishes only what you, or an assistant you have authorised, send or schedule.
Answers that go with this tool
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