Regex Tester & Validator

Matches bold text delimited by asterisks in Telegram Markdown while handling escape sequences. The opening \* matches a literal asterisk, then (.*?) lazily captures the content. Before the closing asterisk, a lookbehind alternation requires that it is NOT preceded by a single backslash (escaped \*) but DOES match when preceded by a double backslash (an escaped backslash followed by a genuine delimiter). Useful for parsing Telegram MarkdownV2 bold formatting without breaking on escaped asterisks.