All Writing & AI Tools Tools
Aesthetic Text Generator
Convert plain text into beautiful aesthetic Unicode styles for social media, bios, and more
AI Image Prompt Generator
Build detailed, optimized prompts for Midjourney, DALL-E, Stable Diffusion, and other AI image generators
AI Persona Generator
Create detailed AI character personas with personality traits, speaking style, and communication rules — download as markdown
AI Prompt Builder
Create structured, effective prompts for ChatGPT, Claude, Midjourney and other AI tools — no signup needed
AI Prompt Word & Token Counter
Count words, characters, and estimate tokens & cost for ChatGPT, Claude, Gemini, and other AI models
Email Subject Line Tester
Score your subject line, detect spam words, preview on mobile and desktop, and get actionable tips
Hashtag Generator
Generate relevant hashtags for Instagram, Twitter, TikTok, and LinkedIn from any topic or keyword
Instagram Caption Counter
Count characters, hashtags, mentions, and emojis in real time. Stay within Instagram's limits and craft the perfect caption.
LinkedIn Post Formatter
Format LinkedIn posts with bold, italic, bullets and live preview before you publish
LLM Model Comparison Chart
Compare GPT-4o, Claude, Gemini, Llama, Mistral, and DeepSeek models side by side — filter by use case, price, and features
LLM Token Cost Comparison
Paste text to estimate token count and compare costs across GPT-4o, Claude, Gemini, and Llama models
Podcast Script Timer
Calculate how long your script takes to read aloud — for podcasts, presentations, and speeches
Reading Time Calculator
Estimate how long it takes to read any text with readability scores, word stats, and frequency analysis
Social Media Image Sizer
Instant dimension reference for every platform and image type — no guessing, no outdated specs
System Prompt Builder
Create structured system prompts for ChatGPT, Claude, and other LLMs with a guided form
Twitter/X Thread Splitter
Split long text into perfectly sized tweets with thread numbering and character counts
Word Counter
Count words, characters, sentences, paragraphs, and get reading & speaking time estimates instantly
Writing Style Analyzer
Analyze readability, sentence structure, vocabulary richness, passive voice usage, and get actionable writing suggestions
Writing & AI Tools on FastTools are free, browser-based tools designed to help you get quick answers without signups or downloads. Every calculator runs entirely in your browser — your data never leaves your device.
Whether you're planning, budgeting, or just curious, these tools are built to be fast, accurate, and private. Pick any tool below to get started instantly.
Frequently Asked Questions
Are these writing & ai tools free?
Yes, every tool is completely free to use with no signup, no account, and no hidden fees.
Is my data safe?
Absolutely. All calculations run locally in your browser. No data is sent to any server or stored anywhere.
Do I need to create an account?
No. Every tool works instantly with no registration required. Just open and start using.