Convert CSV to JSON — the first row becomes the header and each later row an object — or turn a JSON array of objects back into CSV. Both directions speak full RFC 4180: quoted fields, doubled quotes, commas and newlines inside values.
Validation is strict by design: duplicate headers, ragged rows and unterminated quotes are rejected with the exact row and column counts, so data problems surface here instead of silently corrupting a downstream import.
Frequently asked questions
Are numbers kept as numbers?
CSV has no types — every cell stays a string in the JSON output. Cast in your own code, or post-process the JSON.
What if a JSON row has extra keys?
The header comes from the first object; extra keys in later rows are ignored, missing ones become empty cells.
Does it handle Excel exports?
Yes for standard CSV exports; .xlsx is a binary format and needs to be saved as CSV first.
中文说明
CSV 转 JSON——首行作表头、后续每行成一个对象；也可把 JSON 对象数组转回 CSV。两个方向都完整支持 RFC 4180：带引号字段、双写引号、值内的逗号与换行。
校验刻意从严：表头重复、行长不齐、引号未闭合都会连同精确的行列数一起报错，让数据问题在这里暴露，而不是悄悄污染下游导入。
常见问题
数字会保持数字类型吗？
CSV 本身没有类型——JSON 输出里每个单元格都是字符串，请在自己的代码里转换，或对 JSON 做后处理。
JSON 某行多了字段怎么办？
表头取自第一个对象；后续行的多余字段被忽略，缺失字段输出为空单元格。
能处理 Excel 导出的文件吗？
标准 CSV 导出可以；.xlsx 是二进制格式，请先另存为 CSV。