Parse JSON Lines file in the browser with Javascript. http://jsonlines.org/

json_lines.js

function parseJsonLines(file) {
  let results = [];
  for (let i = 0; i < file.length;) {
    const end = file.indexOf('\n', i);

    if (end < 0) {
      end = file.length;
    }

    const currentLine = file.substring(i, end);
    try {
      results.push(JSON.parse(currentLine));
    }
    catch (e) {
      console.error('Skipping broken line ' + currentLine);
    }

    i = end + 1;
  }

  return results;
}