JSONLint is the classic JSON validator -- paste JSON, click Validate, see if it is valid. It works. It is also a bare-bones tool that has not changed much in years, runs ads, and only validates on button click rather than in real time. This is a comparison of JSONLint with the JSON Formatter at Ultimate Tools, which validates and formats as you type. What JSONLint does JSONLint validates JSON and reports the line and position of the first error. It does basic pretty-printing with indentation. The interface is minimal -- textarea in, result out. It has been useful since 2010 and still serves its core purpose.…