The Developer's Utility Belt
Free developer tools, practical calculators and interview preparation resources to help you code faster, learn smarter and prepare for your next opportunity.
Popular Tools
Fast, browser-based developer utilities.
JSON Formatter
Format, validate and minify JSON online for free.
JWT Decoder
Decode JWT tokens and inspect claims securely in your browser.
Base64 Encoder
Encode and decode Base64
UUID Generator
Generate UUID v4 identifiers instantly and securely in your browser.
URL Encoder & Decoder
Encode and decode URLs instantly using a free online URL encoder and decoder.
Password Generator
Generate strong and secure random passwords instantly in your browser.
Timestamp Converter
Convert Unix timestamps to human-readable dates and convert dates to Unix timestamps instantly.
Regex Tester
Test, validate and debug regular expressions online with real-time matching.
Popular calculators
Programming, finance, productivity and utility calculators.
Percentage Calculator
Percentage Calculator online for free.
Age Calculator
Calculate your exact age in years, months and days.
EMI Calculator
Calculate monthly loan EMI, interest payable and total payment.
SIP Calculator
Calculate SIP returns, maturity amount and wealth creation instantly.
Popular Interview Topics
Angular, React, JavaScript, TypeScript and System Design.,
JavaScript Interview Questions
Top JavaScript interview questions and answers for freshers and experienced developers.
Angular Interview Questions
Angular interview questions and answers with practical examples.
ReactJS Interview Questions
Top ReactJS interview questions and answers with practical examples for beginners and experienced developers.
NodeJS Interview Questions
Top NodeJS interview questions and answers for freshers, experienced developers and senior engineers. Includes Event Loop, Streams, Cluster, Worker Threads, Authentication, Security and System Design discussions.
Everything Developers Need
Practical tools and resources for everyday development.
Developer Tools & Resources
DevStacker provides free online developer tools, calculators and interview preparation resources. Every tool runs directly in your browser without installation, sign-up or subscriptions.
Whether you're formatting JSON, decoding JWT tokens, preparing for technical interviews or solving everyday development problems, DevStacker helps you work faster and more efficiently.