What are some alternatives?
When comparing Code2Flow and codepad, you can also consider the following products
Graphviz - Graphviz is open source graph visualization software. It has several main graph layout programs.
Pastebin.com - Pastebin.com is a website where you can store text for a certain period of time.
Chart Mage - Generate sequence diagrams and flowcharts at lightning speed.
GitHub Gist - Gist is a simple way to share snippets and pastes with others.
Elm bot lines - Convert ASCII to SVG diagrams
hastebin - Pad editor for source code.