All Free Online Tools

Browse or filter 61+ free calculators, converters, SEO tools, PDF utilities, AI tools, crypto utilities, health & fitness tools, document tools & developer utilities. Fast, secure, no signup required. Trusted by 100K+ users worldwide.

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61+ Free Tools
100K+ Monthly Users
40+ Countries
0% Data Collection

Welcome to ToolAstra – Your Complete Tool Directory

ToolAstra is a trusted resource for global users looking for fast, accurate, and privacy-friendly online utilities. Our tools are built for creators, investors, business owners, students, developers, and anyone who values time and transparency.

Featured Categories: Health & Fitness · Calculators · Converters · Media Creators · Text/Dev Tools · AI Tools · Crypto Suite

🏥 Health & Fitness

❤️ BMI Calculator

Calculate Body Mass Index based on WHO standards. Track health status and ideal weight.

🔥 BMR Calculator

Calculate Basal Metabolic Rate and TDEE. Find daily calorie needs for weight loss or gain.

🍎 Calorie Calculator

Calculate daily calories based on goals: weight loss, maintenance, or muscle gain.

⚖️ Ideal Weight Calculator

Calculate ideal body weight in kg using medical formulas (Devine, Robinson, Miller).

💧 Water Intake Calculator

Calculate daily water needs based on weight, age, activity level, climate & conditions.

📊 Body Fat Calculator

Calculate body fat % using US Navy Method or BMI. Track lean body mass and fat mass.

📐 Waist-Hip Ratio

Calculate WHR, check health risk, and classify body shape (Apple, Pear, Hourglass).

🥗 Macro Calculator

Calculate daily macros (protein, carbs, fat) for weight loss, muscle gain, or keto.

🧮 Financial & Scientific Calculators

🏠 EMI Calculator

Calculate monthly loan EMI for home, car, personal loans. See amortization schedule.

🧾 GST Calculator

Add or remove GST using latest Indian tax rates. Calculate GST amount instantly.

% Percentage Calculator

Calculate percentages, percentage increase/decrease, discounts, and ratios.

🎂 Age Calculator

Find exact age in years, months, and days from your birthdate.

💰 RPM Earnings Calculator

Convert RPM and pageviews into real ad revenue in USD, INR, and USDT.

📅 Date Difference Calculator

Calculate days, months, and years between two dates instantly.

📊 AdSense Earnings Calculator

Estimate daily, monthly, and yearly Google AdSense income using RPM, CTR, and CPC.

📈 SIP Calculator

Plan monthly mutual fund investments. See total investment and maturity value.

💵 Compound Interest Calculator

See how one-time investments grow with compound interest over time.

⚖️ Break-Even Calculator

Find units and revenue needed to cover fixed and variable costs.

🏠 General EMI Calculator

Home, Car, Personal Loan EMI Planner

🎓 Education Loan EMI

Student Loan & Moratorium Calculator

💼 Business Loan EMI

Mudra, CGTMSE & SME Loan Planner

🔄 Converters, PDF & Formatters

💱 Currency Converter

Live forex rates for 150+ currencies. Convert USD, EUR, INR, GBP, JPY, AED instantly.

📐 Unit Converter

Convert length, weight, temperature, area, volume, speed, and 100+ other units.

{ } JSON Formatter

Beautify, minify, and validate JSON safely for developers. Check syntax errors.

🔗 URL Encoder/Decoder

Encode URLs for safe sharing and decode percent-encoded text instantly.

🔐 Base64 Encoder/Decoder

Convert text or files to and from Base64 encoding. 100% client-side, secure.

PDF Merger

Combine multiple PDF files into one document instantly. Works offline, privacy-first, no upload limits.

📦 PDF Compressor

Reduce PDF file size for email and uploads without losing readability.

🖼️ Image to PDF Converter

Convert JPG/PNG photos and scans into clean multi-page PDFs instantly.

🎨 Media Creators & Generators

📸 Instagram Hashtag Generator

Find the best hashtags for your posts, reels & stories. Boost reach, engagement & followers with optimized tags.

🎬 YouTube Thumbnail Downloader

Download high-resolution YouTube video thumbnails in HD, SD, and max quality.

📱 QR Code Generator

Create custom QR codes for URLs, text, WiFi, contacts, and payments.

🖼️ Image Compressor

Compress and resize images online without quality loss for web and social media.

🔊 Text to Speech

Convert text to natural-sounding speech instantly. Multiple voices supported.

💻 Text, SEO & Developer Tools

🔍 Keyword Density Checker

Analyze keyword frequency & density in your content. Best SEO tool to avoid keyword stuffing & optimize articles.

🎨 CSS Generators Bundle

Create Box Shadows, Gradients, Border Radius & Text Shadows with live preview and copy-paste code.

📝 Plagiarism Checker

Free plagiarism checker to detect duplicate content online. Check your text for originality, privacy-first.

📝 Word Counter

Count words, characters, sentences, and paragraphs for writers and SEO.

📋 Compare Text

Find differences between two text blocks for editing and code comparison.

🔑 Password Generator

Generate strong, secure random passwords with letters, numbers, and symbols.

🤖 AI Tools, Detectors & Generators

🔍 AI Content Detector

Free AI checker to detect AI-generated text from ChatGPT, GPT-5, Gemini, Claude & more. Analyzes perplexity, burstiness & sentence variation.

️ AI Image Prompt Generator

Free AI image prompt generator for Midjourney, DALL-E 3, Stable Diffusion & Google Gemini. 20+ art styles, copy & paste ready prompts.

Perplexity AI

AI-powered search engine with real-time answers and sources. Research made easy.

Claude AI

Smart AI assistant by Anthropic for writing, coding, analysis, and generating ideas.

✍️ Copy AI

AI copywriting tool for marketing content, ads, emails, social media posts, and blogs.

Notion AI

AI-powered note-taking, summarizing, and brainstorming for productivity.

✨ AI Caption Generator

Generate viral Instagram, Pinterest & YouTube captions instantly. Multiple tones.

#️⃣ AI Hashtag Generator

Create trending hashtags for Instagram, TikTok, YouTube & Pinterest. Boost reach.

🪙 Crypto Suite & Trading Tools

💱 Crypto Converter

Convert BTC, ETH, USDT & 100+ altcoins to USD, INR, EUR, GBP, AED. Live rates.

₿ Bitcoin USD/INR Converter

Quick BTC to USD, INR, EUR, GBP, AED conversion. Perfect for value checks.

📊 Crypto Price Tracker

Live cryptocurrency prices with auto-refresh. Track Bitcoin, Ethereum, and top coins.

📈 Crypto Profit Calculator

Calculate trading profit/loss and ROI percentage. Track gains and breakeven points.

📋 Crypto Tax Estimator

Estimate capital gains tax on crypto trades. Supports India, USA, Europe & worldwide.

💰 DCA Calculator

Calculate Dollar-Cost Averaging returns. See average buy price and total returns.

🏦 Staking Rewards Calculator

Calculate annual and monthly staking APY returns. Plan your passive income.

⛽ ETH Gas Fee Estimator

Estimate Ethereum network gas fees in Gwei. Calculate transaction costs in USD/INR.

🪙 Solana Staking Calculator

Free Solana staking calculator to estimate SOL rewards, APY & yearly earnings. Learn how much SOL to stake and calculate passive income instantly.

Frequently Asked Questions (FAQ)

❓ How often do you add new tools?
We typically add 2-3 new utilities every month. Our latest additions include Keyword Density Checker, PDF Merger, Instagram Hashtag Generator, CSS Generators Bundle, Solana Staking Calculator, AI Content Detector, AI Image Prompt Generator, Body Fat Calculator, Waist-Hip Ratio Calculator, Water Intake Calculator, Macro Calculator, and Ideal Weight Calculator. You can suggest ideas via our contact form.
❓ Are all tools really free and privacy-first?
Yes! All 61+ tools are 100% free with no hidden fees. They work entirely client-side in your browser, meaning your data never leaves your device. We don't collect, store, or share any personal information.
❓ What does the Keyword Density Checker do?
Our Keyword Density Checker analyzes the frequency and density of keywords in your content. It helps you optimize articles for SEO by identifying overused terms (keyword stuffing) and underused keywords, ensuring a healthy 1-2% density for your primary keywords.
❓ How does the PDF Merger work?
The PDF Merger combines multiple PDF files into one document. You can drag and drop PDFs, reorder them, and merge them into a single file. It works 100% in your browser — no files are uploaded to any server, ensuring complete privacy.
❓ What is the CSS Generators Bundle?
The CSS Generators Bundle includes four powerful generators: Box Shadow, Border Radius, Gradient, and Text Shadow. Each provides a visual interface with sliders and color pickers to customize effects, with a live preview and one-click copy for the generated CSS code.
❓ How does the Instagram Hashtag Generator work?
Enter your topic or niche (e.g., "fitness motivation", "vegan recipes") and the Instagram Hashtag Generator provides a curated mix of popular, niche, and trending hashtags. Use the mix of categories to maximize your reach and engagement on posts and reels.
❓ What does the Body Fat Calculator do?
Our Body Fat Calculator calculates your body fat percentage using the US Navy Method (based on waist, neck, hip measurements) or BMI method. It also shows your lean body mass, fat mass, and classification (Athlete, Fitness, Average, Obese).
❓ How does the Waist-Hip Ratio Calculator work?
The Waist-Hip Ratio Calculator divides your waist circumference by your hip circumference to assess health risk. It classifies your body shape (Apple, Pear, Hourglass, Rectangle, Inverted Triangle) and shows health risk based on WHO guidelines.
❓ What is the Macro Calculator for?
The Macro Calculator calculates your daily protein, carbohydrate, and fat targets based on your weight, activity level, and goal (lose weight, maintain, or gain muscle). It includes presets for Balanced, High Protein, Keto, and the 40/40/20 rule.
❓ Can I use these tools for business purposes?
Absolutely! Our calculators and converters are used by professionals, businesses, and enterprises worldwide for trading, content creation, and development. You're free to use them for commercial projects.
❓ Do these tools work offline?
Yes! Once loaded, most tools work without internet since all processing happens locally in your browser using JavaScript.
❓ Which countries can use ToolAstra tools?
ToolAstra is available worldwide! We serve users in 40+ countries including USA, India, UK, Canada, Australia, UAE, and across Europe and Asia. All tools support multiple currencies and are optimized for global users.

Explore Our Complete Tool Collection!

From Keyword Density Checker and PDF Merger to Instagram Hashtag Generator and CSS Generators — all 61+ tools are 100% free and ready to use right now.

🔍 → Keyword Density Checker  |  → PDF Merger  |  📸 → Instagram Hashtag Generator  |  → CSS Generators  |  🪙 → Solana Staking  |  🤖 → AI Content Detector

Need Help? 📧 Email: support@toolastra.com | 💬 Contact: Contact Form