Python Dict to JSON Online

This syntax transformation tool converts Python dictionary literal strings into standards-compliant JSON output by applying a sequence of lexical transformations that bridge the incompatibilities between Python and JSON notation. The core conversion engine implements a character-by-character state machine parser that tracks string context boundaries to safely transform single-quoted strings to double-quoted JSON strings without corrupting escaped characters or nested quotation marks.

The transformation pipeline handles five critical Python-to-JSON incompatibilities. First, Python's True and False boolean literals map to JSON's lowercase true and false via word-boundary-aware regex replacement. Second, Python's None value converts to JSON null. Third, single-to-double quote conversion processes each character with awareness of escape sequences, preventing corruption of strings containing apostrophes or pre-existing double quotes. Fourth, trailing comma removal strips the final comma before closing braces and brackets that Python permits but JSON forbids. Fifth, Python tuple parentheses convert to JSON array brackets.

Output undergoes JSON.parse validation followed by JSON.stringify pretty-printing with 2-space indentation, ensuring syntactic correctness before display. Error messages surface parser failures with position information helping users locate problematic syntax. The dual-pane editor interface provides Python syntax highlighting on the input side using Prism.js Python grammar and JSON highlighting on the output, with file upload and download capabilities.