Formatters

JSON Formatter
HTML Formatter
XML Formatter
SQL Formatter

Validators

JSON Validator
HTML Validator
XML Validator - XSD
XPath Tester
Credit Card Number Generator & Validator
Regular Expression Tester (RegEx)
Java Regular Expression Tester (RegEx)
Cron Expression Generator - Quartz

Encoders & Decoders

Url Encoder & Decoder
Base 64 Encoder & Decoder
Convert File Encoding
QR Code Generator

Code Minifiers / Beautifier

JavaScript Beautifier
CSS Beautifier
JavaScript Minifier
CSS Minifier

Converters

XSD Generator
XSLT (XSL Transformer)
XML to JSON Converter
JSON to XML Converter
CSV to XML Converter
CSV to JSON Converter
Epoch Timestamp To Date

Cryptography & Security

Message Digester (MD5, SHA-256, SHA-512)
HMAC Generator
MD5 Generator
SHA-256 Generator
SHA-512 Generator

String Escaper & Utilities

String Utilities
HTML Escape
XML Escape
Java and .Net Escape
JavaScript Escape
JSON Escape
CSV Escape
SQL Escape

Web Resources

Lorem Ipsum Generator
List of MIME types
HTML Entities
Url Parser / Query String Splitter
i18n - Formatting standards & code snippets
ISO country list - HTML select snippet
USA state list - HTML select snippet
Canada province list - HTML select snippet
Mexico state list - HTML select snippet
Time zone list - HTML select snippet