DevToys is an Open-Source Swiss Army knife for developers created by a Microsoft Visual Studio engineer. DevToysMac is also available.

DevToys features a clean interface with categories to choose from, including:

Converters
Json Yaml
Number Base
Encoders / Decoders
HTML
URL
Base64
JWT Decoder
Formatters
Json
Generators
Hash (MD5, SHA1, SHA256, SHA512)
UUID 1 and 4
Lorem Ipsum
Text
Inspector & Case Converter
Regex Tester
Text Comparer
Markdown Preview
Graphic
Color Blindness Simulator
PNG / JPEG Compressor

Ссылка: ..