Free Developer Tools, Calculators & Interview Prep

Fast, privacy-friendly utilities and interview questions for developers, DevOps engineers, and students. No login. No tracking. 100% free.

Popular Developer Tools

JSON Formatter

Beautify, format, and validate JSON instantly.

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JWT Decoder

Decode JWT header and payload securely.

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Base64 Tool

Convert text to and from Base64 format.

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Recently Added

UUID Generator

Generate UUID v4 or time-based UUID v1.

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Recently Added

Timestamp Converter

Convert Unix timestamps to readable dates.

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Popular Calculators (India)

EMI Calculator

Calculate loan EMI for home, car, or personal loans.

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CTC to In-Hand

Estimate monthly take-home salary from CTC.

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Income Tax

Estimate income tax under Indian tax slabs.

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Interview Questions

Linux Interview

Basic to advanced Linux interview questions with real-world admin scenarios.

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AWS Interview

AWS interview questions covering EC2, VPC, IAM, architecture, and scenarios.

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New

DevOps Interview

50+ DevOps interview questions covering Docker, CI/CD, Kubernetes, and SRE.

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Security & Authentication Explainers

In-depth guides explaining authentication, security, and API concepts used in modern web applications and real-world systems.

What is JWT?

Learn how JSON Web Tokens work, their structure, and where they are used in authentication and APIs.

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OAuth vs JWT vs Session

A practical comparison of authentication methods, with real-world use cases and trade-offs.

Compare →

Hashing vs Encryption

Understand the difference between hashing and encryption, with secure coding examples and best practices.

Learn Security →

API Authentication Methods

Explore API authentication options including API keys, JWT, OAuth 2.0, and mTLS.

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JWT Security Attacks

Learn common JWT vulnerabilities like alg=none, token replay, and how to mitigate them.

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Why use utils.preriskai.com?

utils.preriskai.com is designed to provide fast, reliable, and privacy-friendly tools for everyday development, DevOps, and learning needs. Every tool on this site is built with a focus on simplicity, accuracy, and real-world usability.

No login or signup required: All tools are instantly accessible without creating an account or sharing personal information.
No data storage or tracking: Inputs are processed only for the current request and are never stored, logged, or shared.
Fast, lightweight, and mobile-friendly: Optimized for quick results on desktop and mobile devices.
Built for real-world use: Created for developers, DevOps engineers, interview preparation, and continuous learning.