The latest articles on DEV Community by Subasis (@studyin_widget_14521287e3). https://dev.to/studyin_widget_14521287e3 https://media2.dev.to/dynamic/image/width=90,height=90,fit=cover,gravity=auto,format=auto/https:%2F%2Fdev-to-uploads.s3.us-east-2.amazonaws.com%2Fuploads%2Fuser%2Fprofile_image%2F3853982%2F2a0f975b-e073-46ba-99f3-e3ff4c064c93.png https://dev.to/studyin_widget_14521287e3 en Subasis Tue, 31 Mar 2026 17:59:02 +0000 https://dev.to/studyin_widget_14521287e3/i-built-20-free-online-tools-age-calculator-emi-json-formatter-heres-what-i-learned-4jjh https://dev.to/studyin_widget_14521287e3/i-built-20-free-online-tools-age-calculator-emi-json-formatter-heres-what-i-learned-4jjh <h1> I Built 20+ Free Online Tools – Here’s What I Learned </h1> <p>Over the past few weeks, I built a collection of 20+ free online tools for developers and everyday users.</p> <p>👉 You can try it here: <a href="https://mokshhub.com/" rel="noopener noreferrer">https://mokshhub.com/</a></p> <h2> 🚀 What I Built </h2> <p>Some of the tools include:</p> <ul> <li>Age Calculator </li> <li>EMI Calculator </li> <li>SIP Calculator </li> <li>JSON Formatter </li> <li>Word Counter </li> <li>Salary Tax Calculator (India) </li> </ul> <p>You can explore all tools here:<br><br> 👉 <a href="https://mokshhub.com/" rel="noopener noreferrer">https://mokshhub.com/</a></p> <h2> 💡 Why I Built This </h2> <p>I noticed that many existing tools are:</p> <ul> <li>Slow </li> <li>Filled with ads </li> <li>Not mobile-friendly </li> </ul> <p>So I wanted to build:</p> <ul> <li>Fast ⚡ </li> <li>Clean UI 🎯 </li> <li>No sign-up required 🔐 </li> </ul> <h2> 🔧 Tech Stack </h2> <ul> <li>React </li> <li>Vite </li> <li>Tailwind CSS </li> </ul> <h2> 📊 Challenges Faced </h2> <ul> <li>Handling date calculations accurately (leap years, etc.) </li> <li>Optimizing performance </li> <li>Structuring SEO for a React app </li> </ul> <h2> 🔗 Try These Tools </h2> <p>Here are a few direct links:</p> <ul> <li>Age Calculator: <a href="https://mokshhub.com/age-calculator" rel="noopener noreferrer">https://mokshhub.com/age-calculator</a> </li> <li>EMI Calculator: <a href="https://mokshhub.com/emi-calculator" rel="noopener noreferrer">https://mokshhub.com/emi-calculator</a> </li> <li>JSON Formatter: <a href="https://mokshhub.com/json-formatter" rel="noopener noreferrer">https://mokshhub.com/json-formatter</a> </li> </ul> <h2> 🙌 Feedback Welcome </h2> <p>I’d love your feedback:</p> <ul> <li>What tools should I add next? </li> <li>Any improvements needed? </li> </ul> <p>Thanks for reading!</p> webdev javascript react opensource