draw.io - Online diagramming application
CpConverter - Code Page Converter - Convert HTML/Text files to different encoding formats e.g.
LucidChart - LucidChart is the missing link in online productivity suites. LucidChart allows users to create, collaborate on, and publish attractive flowcharts and other diagrams from a web browser.
Batch Encoding Converter - Convert files between more than 100 text encodings and binary formats!
PlantUML - PlantUML is an open-source tool that uses simple textual descriptions to draw UML diagrams.
CONVERTCP - CONVERTCP is a command line utility to convert text file encoding.