Developer Tools
Essential utilities for developers - JSON, Base64, JWT, regex, hash, UUID, and more.
All 31 tools below are 100% free, need no signup, and run entirely in your browser — your files never leave your device.
Developer tools you reach for a dozen times a day — format and validate JSON, encode and decode Base64, decode JWTs, test regular expressions, generate UUIDs and hashes, and convert between data formats. Everything runs in your browser, so payloads, tokens and secrets never touch a server. No installs, no sign-up, no rate limits — just open a tool and paste. Bookmark the ones you use most; they load instantly and work offline once cached.
All Developer Tools
JSON Formatter
Format, validate, and beautify JSON online for free. Instantly pretty-print or minify JSON with syntax highlighting.
Base64 Encode/Decode
Encode or decode Base64 strings online instantly. Free Base64 encoder and decoder with URL-safe mode support.
JWT Decoder
Decode and inspect JWT tokens online. View header, payload, and signature of any JSON Web Token instantly.
UUID Generator
Generate random UUID v4 strings online. Create single or bulk UUIDs instantly for free.
Hash Generator
Generate MD5, SHA-1, SHA-256, and SHA-512 hashes online. Free cryptographic hash calculator.
URL Encoder/Decoder
Encode or decode URLs online for free. Percent-encode special characters or decode encoded URL strings instantly.
HTML Encoder/Decoder
Encode or decode HTML entities online. Convert special characters to HTML entities and back.
Regex Tester
Test and debug regular expressions online. Real-time regex matching with match highlighting and group capture display.
Timestamp Converter
Convert Unix timestamps to human-readable dates and vice versa. Current timestamp, epoch converter online.
Color Converter
Convert colors between HEX, RGB, HSL, and RGBA formats online. Free color picker and converter.
Password Generator
Generate strong, random passwords instantly. Customize length, character types, and quantity for maximum security.
Base Converter
Convert numbers between binary, octal, decimal, and hexadecimal bases online. Instant live conversion as you type.
Unit Converter
Convert between units of length, weight, temperature, area, volume, speed, and data online. Free instant unit conversion.
CSS Minifier
Minify and compress CSS to reduce file size, or beautify minified CSS back to readable format. Free online CSS minifier.
HTML Minifier
Minify HTML to reduce file size or beautify minified HTML into readable code. Free online HTML minifier and formatter.
JS Formatter
Beautify and format JavaScript code online for free. Or minify JS to reduce file size. Fast browser-based JS formatter.
Percentage Calculator
Calculate percentages online — find X% of a number, what percent X is of Y, percentage change, and reverse percentage lookups.
Age Calculator
Calculate exact age in years, months, and days from a birth date. Find total days, weeks, months lived, and days to next birthday.
BMI Calculator
Calculate your Body Mass Index (BMI) online. Supports metric (kg/cm) and imperial (lb/ft). Shows BMI category and ideal weight range.
Password Strength
Check how strong your password is instantly. Get a detailed security score, entropy estimate, and specific tips to improve it.
Cron Parser
Parse and understand cron expressions online. See human-readable descriptions and the next 5 scheduled run times. Free cron job tool.
What Is My IP
See your public IP address instantly, with its location, ISP, ASN and timezone. Plus a free IP lookup to check any IPv4 or IPv6 address. No signup.
Loan Calculator
Calculate monthly EMI, total interest, and total payment for any loan. Supports multiple currencies with full amortization schedule.
Random Number
Generate random numbers in any range. Generate single or multiple random numbers, with or without repeats. Cryptographically secure.
JSON to TypeScript
Generate TypeScript interfaces from any JSON object automatically. Paste JSON and get ready-to-use TypeScript types instantly.
Gradient Generator
Create beautiful CSS gradients online. Design linear, radial, and conic gradients with a live preview and copy CSS instantly.
Text to Binary
Convert text to binary, hexadecimal, or decimal encoding online for free. Or decode binary/hex/decimal back to readable text.
Email Validator
Validate single or bulk email addresses online for free. Detailed checks for format, domain, TLD, and common errors.
SQL Formatter
Format and beautify SQL queries online for free. Uppercase keywords, indent clauses, and make SQL readable in one click.
Test Data Generator
Generate unlimited realistic fake data for testing — names, emails, phones, addresses, companies, UUIDs. Export as CSV, JSON, or SQL.
Barcode Generator
Generate Code 128 barcodes free — one at a time, or in bulk from a CSV/list and download all as a ZIP of PNGs. No signup, runs in your browser.
How-to guides
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Tool collections
Frequently asked questions about developer tools
Are these developer tools safe for sensitive data like tokens?
Yes. Every tool runs entirely client-side in your browser. Nothing you paste — JSON, JWTs, API keys — is uploaded or logged, so it never leaves your machine.
Do I need to install or sign up for anything?
No. All tools are free to use with no account, no extension and no installation. Open the page and start working.
Do the tools work offline?
Once a tool page has loaded, most keep working without a connection because the processing happens in your browser, not on a server.