2026-06-15 · 8 min read
JSON, CSV, and XML: exchanging structured data
Convert API responses and legacy XML feeds into spreadsheets and back — with validation tips.
Modern APIs speak JSON; enterprise systems still ship XML; analysts live in Excel. Browser converters handle quick transforms when you receive a data file by email and need it in another shape before end of day — without installing Python or Node on a corporate laptop.
JSON to CSV for spreadsheet analysis
JSON arrays of objects flatten to columns automatically. Nested objects become dotted column names or JSON strings in cells — inspect the header row before pivoting.
Large JSON files may exceed browser memory; filter at the source API when possible or split arrays.
CSV to JSON for apps and configs
CSV to JSON produces an array of row objects with headers as keys. Empty cells become empty strings — handle nulls in your app if needed.
Quote-heavy CSV (commas inside fields) requires proper RFC 4180 quoting; malformed vendor CSV may need manual repair in a text editor first.
XML format and readability
Our XML Format tool pretty-prints minified XML so you can read nested structures before writing XPath or mapping fields. It does not validate against XSD schemas — use enterprise tools for strict validation.
Huge XML logs may slow the browser; open subsections or use streaming desktop tools for multi-gigabyte files.
Common data exchange mistakes
Do not assume JSON numbers survived Excel — Excel may display IDs in scientific notation. Import CSV with columns as text for ID fields.
Time zones in ISO dates may shift when Excel auto-converts to locale dates — keep dates as strings when precision matters.
Privacy for business data exports
Customer lists, payroll extracts, and API dumps contain PII. Browser-local JSON/CSV conversion keeps files on your device — preferable to uploading to random online formatters.
Delete downloaded outputs from Downloads folder on shared PCs after use.
Security reminder
Customer lists, payroll exports, and API dumps contain PII. Browser-local conversion avoids sending rows to random online formatters — still delete outputs from Downloads on shared machines after use.
Never email unencrypted sensitive CSV/JSON unless policy allows.