Fydler UtilityBelt - CSV ↔ JSON Converter

CSV ↔ JSON Converter

Data & Formatting Tool

CSV Input

JSON Output

About CSV & JSON

CSV (Comma-Separated Values) is a simple tabular format supported by spreadsheets. JSON (JavaScript Object Notation) is a structured data format. The converter supports quoted fields and multi-line values.

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lucide.createIcons(); let cjMode = 'csv2json'; function setCJMode(mode) { cjMode = mode; document.querySelectorAll('.cj-mode-btn').forEach(b => b.classList.remove('btn-primary')); document.querySelectorAll('.cj-mode-btn').forEach(b => b.classList.add('btn-outline')); const btn = mode === 'csv2json' ? document.getElementById('cj-c2j') : document.getElementById('cj-j2c'); btn.classList.remove('btn-outline'); btn.classList.add('btn-primary'); document.getElementById('cj-input-label').textContent = mode === 'csv2json' ? 'CSV Input' : 'JSON Input'; document.getElementById('cj-output-label').textContent = mode === 'csv2json' ? 'JSON Output' : 'CSV Output'; convertCJ(); } function convertCJ() { const input = document.getElementById('cj-input').value; const output = document.getElementById('cj-output'); const error = document.getElementById('cj-error'); if (!input.trim()) { output.value = ''; error.textContent = ''; return; } try { if (cjMode === 'csv2json') { const lines = input.trim().split(/\r?\n/); if (lines.length < 2) throw new Error('CSV must have at least a header row and one data row.'); const headers = parseCSVLine(lines[0]); const result = []; for (let i = 1; i < lines.length; i++) { const vals = parseCSVLine(lines[i]); if (vals.length === 1 && vals[0] === '') continue; const obj = {}; headers.forEach((h, idx) => { obj[h.trim()] = (vals[idx] || '').trim(); }); result.push(obj); } output.value = JSON.stringify(result, null, 2); } else { const arr = JSON.parse(input); if (!Array.isArray(arr)) throw new Error('JSON must be an array of objects.'); if (arr.length === 0) throw new Error('Array is empty.'); const headers = Object.keys(arr[0]); const lines = [headers.join(',')]; for (const obj of arr) { const vals = headers.map(h => { const v = String(obj[h] ?? ''); if (v.includes(',') || v.includes('"') || v.includes('\n')) { return '"' + v.replace(/"/g, '""') + '"'; } return v; lines.push(vals.join(',')); } output.value = lines.join('\n'); } error.textContent = ''; } catch(e) { error.textContent = e.message; output.value = ''; } } function parseCSVLine(line) { const result = []; let current = ''; let inQuotes = false; for (let i = 0; i < line.length; i++) { const c = line[i]; if (inQuotes) { if (c === '"') { if (i + 1 < line.length && line[i + 1] === '"') { current += '"'; i++; } else { inQuotes = false; } } else { current += c; } } else { if (c === '"') { inQuotes = true; } else if (c === ',') { result.push(current); current = ''; } else { current += c; } } } result.push(current); return result; } document.getElementById('cj-input').addEventListener('input', convertCJ); document.getElementById('cj-copy-btn').addEventListener('click', () => { const v = document.getElementById('cj-output').value; if (v) { navigator.clipboard.writeText(v); showToast('Copied!'); } }); function showToast(msg) { const toast = document.getElementById('toast'); const toastMsg = document.getElementById('toast-message'); toastMsg.textContent = msg; toast.classList.add('show'); setTimeout(() => toast.classList.remove('show'), 2000); }