Free AI caption generator for Instagram, TikTok, LinkedIn and more

What this caption generator does, and what it does not

It writes post captions: the text that sits under a photo, Reel, TikTok, pin or link. You type what the post is about, and a language model returns five options shaped by the platform's habits, the tone and the language you chose.

It does not add subtitles or closed captions to a video, and it does not read an image. Many tools that rank for 'caption generator' do video subtitles; this is not one of them. It also leaves hashtags and emojis to you, so the caption stays clean and you control where tags go.

What to type for better captions

The model can only use what you give it. A specific detail beats a long description. Name the product, the reason to care now, and one fact nobody else can claim. Some inputs that work, by niche:

• Coffee shop: new Ethiopia Guji light roast, blueberry notes, roasted Tuesday, ships in 48 hours
• Gym: 6 a.m. class is back, 30 minutes, beginners welcome, first class free
• Real estate: 3-bed with a south-facing garden, open house Saturday 11 to 1
• SaaS: new CSV import, takes 10 seconds instead of 10 minutes
• Restaurant: fall menu launch, squash risotto, walk-ins only this week
• Online store: restock of the linen shirt in sage, sizes S to XL

Caption length by platform in 2026

Every network has a hard limit and a much smaller visible limit before the 'more' link. The visible part is the one that matters, because most people never tap. The tool writes to the numbers on the right.

• Instagram: 2,200 characters, about 125 visible. Hook in line one, 1 to 3 short paragraphs
• TikTok: 4,000 characters, about 100 visible. The tool stays under 150
• X: 280 characters (more for Premium). The tool stays under 240
• Threads: 500 characters. The tool stays under 300, often ending on a question
• Bluesky: 300 characters. The tool stays under 280
• LinkedIn: 3,000 characters, about 210 visible on desktop. First line earns the click
• Facebook: long posts allowed; 1 to 3 plain sentences read best
• YouTube: 5,000-character description. The tool writes the opening 1 to 2 sentences
• Pinterest: 500-character description. The tool writes under 200, keyword first

Example captions for a coffee roaster, platform by platform

Here is one post, a new single-origin coffee from the fictional roaster Acme Coffee, written the way each platform wants it. Same facts, different shape.

• Instagram: Blueberry, jasmine, a little honey. Our new Ethiopia Guji tastes nothing like the coffee you grew up with. Roasted light on Tuesday, at your door by Thursday. Brew it as a pour-over and let it cool a minute. Link in bio.
• TikTok: Light roast that tastes like blueberries. No syrup. Just a bean from Guji, Ethiopia.
• X: Our Ethiopia Guji is back. Light roast, blueberry and jasmine, roasted Tuesday and on your doorstep by Thursday.
• Threads: Light roasts are not sour, they are brewed too fast. Our new Guji proves it. Pour-over or French press, which one do you use?
• LinkedIn: We stopped roasting to stock. Every Acme Coffee bag now ships within 48 hours of roasting. Here is what that changed for a six-person roastery.
• Facebook: New on the shelf: Ethiopia Guji, a light roast with blueberry and jasmine notes. Grab a bag at the Main Street café or order online.
• Pinterest: Light roast Ethiopian coffee for pour-over. Acme Coffee Guji, blueberry and jasmine notes. Brew ratio: 15 g coffee to 250 g water.

How to write a caption people read

Put the reason to stop in the first line: a number, a claim, a question or the start of a story. Say one thing per post and ask for one action, whether that is save, reply, tap the link or visit. Use the words people search for, because Instagram and TikTok search read captions. Break long captions into short lines.

That is why each run gives five angles instead of five rewordings: a hook, a question, a benefit, a short story and a direct line. You see which approach fits the photo and the week, then edit in the detail only you know. Generated text is a draft, not a finished post.

Hashtags and emojis go on last

The generator leaves both out on purpose. Instagram has capped posts and Reels at five hashtags since December 2025, so a caption stuffed with tags will not even publish. On LinkedIn, three or fewer look natural; on X and Bluesky, none is usually better. Add emojis where they carry meaning, not at the end of every line. For the tags themselves, the free hashtag generator returns a set of broad, niche and specific ones for the same post.