AI tools that write your captions
AIUtilBox gives creators, marketers and students free tools for Instagram, LinkedIn and YouTube, plus prompt tools for ChatGPT, Claude, Gemini and Midjourney.
Social media tools
Write captions, bios, headlines, posts, hashtags and video titles in seconds.
Instagram Caption Generator
6 scroll-stopping captions with hooks, a call to action and hashtags.
Open tool →IGInstagram Bio Generator
Bio ideas that fit Instagram's 150-character limit.
Open tool →inLinkedIn Headline Generator
Professional headlines from your role, skills and wins.
Open tool →inLinkedIn Post Generator
Turn a few points into an engaging LinkedIn post.
Open tool →Popular#Hashtag Generator
Keyword, niche and popular hashtags for any platform.
Open tool →YTYouTube Title Generator
10 click-worthy titles with your keyword up front.
Open tool →AI prompt tools
Get better answers from ChatGPT, Claude, Gemini and Midjourney.
AI Prompt Generator
Structured prompts for ChatGPT, Claude and Gemini.
Open tool →02Image Prompt Generator
Detailed prompts for Midjourney, Stable Diffusion and more.
Open tool →03Prompt Improver
Turn a vague prompt into a stronger one.
Open tool →04AI Token Counter
Estimate tokens, context use and API cost.
Open tool →05ChatGPT Prompt Templates
Copy-and-paste prompts for everyday tasks.
Open tool → NewDBAI Tools Directory
47 of the best AI tools, sorted by category and price.
Browse tools →Fast, free and private
Free forever
Every tool is free to use. No trials, no credit card, no limits.
No sign-up
Open a tool and start. You never need an account.
Private by design
Tools run in your browser, so your text is never uploaded to our servers.
Works on any device
Built for phones first, so you can create posts on the go.
Frequently asked questions
Are AIUtilBox tools really free?
Yes. Every tool on AIUtilBox is free and needs no account.
Do I need ChatGPT or another AI subscription?
No. Our tools work on their own in your browser. The prompts you create also work in the free versions of most AI assistants.
Is my data safe?
Your text stays in your browser and isn't sent to our servers. See our Privacy Policy for details.
Can I suggest a new tool?
Yes, please do. Send your idea through our contact page.