Where did the leading zeros in my CSV go?

Treat identifiers as text

id,postal_code,note
00123,010010,"Hello, world"
00456,000001,"two
lines"

In PlainKit CSV → JSON, the identifier stays the string "00123". Spreadsheet type inference may display it as 123. Import identifier columns as text and inspect the raw file after saving.

Conversion is not lossless serialization

[
  {"id":"00123","note":null,"meta":{"tier":1}},
  {"id":"00456","note":""}
]

This tool exports null and missing values as empty cells, and nested objects as JSON text. Converting back produces strings, not the original nulls, missing fields, or objects. Keep the source JSON and a schema when these distinctions matter.

Use formula protection and verify

Spreadsheet applications can interpret formula-like cell text. PlainKit prefixes risky cells and headers with an apostrophe by default. This changes the text and is not a universal guarantee for every importer.

• Check headers and record counts after conversion.
• Test cells containing commas, quotes, and line breaks.
• Agree on encoding, delimiters, types, and null representation.