UnicodeChecker

Exploration

• Unicode number and UTF encodings for each codepoint
• Related codepoints and decomposition
• Browsing by plane, codepoint number or character block
• Unihan data such as definitions, variants, pronunciations and older encodings for many Asian codepoints
• Finding code points by name or their Unihan definition
• Finding codepoints via Spotlight

Conversion 

• To and from: HTML, CSS, URLs, IDNA and various programming languages
• Unicode Normalisation with an indication whether the string is already normalised (NFC, NFKC, NFD and NFKD)
• Split Up and Diff tools to analyse a string codepoint by codepoint and highlight the differences
• Most of the features are available to all applications you use via the ‘Services’ menu and AppleScript.