CSV ⇄ JSON Converter

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Convert CSV to JSON and back with an RFC-4180-safe parser — quoted fields, embedded commas and newline traps all handled.

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Key features

  • CSV → JSON with a strict RFC-4180 state-machine parser: quoted fields, escaped quotes ("") and commas or newlines inside quotes stay literal.
  • Delimiter selector for comma, semicolon, tab or pipe inputs.
  • CSV options: treat first row as header (otherwise column_1, column_2…), trim whitespace per cell, and auto-detect types (42 → number, true → boolean, empty → null).
  • Type detection keeps leading-zero strings like 007 as text, so IDs and ZIP codes don't get mangled.
  • JSON → CSV accepts arrays of flat objects (union of all keys becomes columns) or arrays of arrays, with an include-header switch.
  • Ragged rows produce explicit warnings (row number, fields found vs expected) and downloads as .json or .csv.

How it works

  1. Pick the direction

    Use the CSV → JSON tab for spreadsheet data, or JSON → CSV to flatten API results back into rows.

  2. Paste the input and set options

    Paste data on the left, choose the delimiter, and flip the header/trim/type switches to match your source. Output updates live (with a short debounce for big pastes).

  3. Check warnings and stats

    Ragged rows are called out by row number instead of silently padded; tiles show row count, column count and output size.

  4. Copy or download

    Copy the result, or download it as dailywebtools-converted.json / dailywebtools-converted.csv. The Load sample button demonstrates tricky quoting in one click.

Tips for better results

  • The sample CSV deliberately includes a comma inside a name, escaped quotes and a value spanning two lines — use it to verify your own tricky files.
  • Disable auto-detect types if you need every cell to stay a string, e.g. when product codes must remain text.
  • Duplicate header names are allowed; the later column wins the key — rename headers first if that matters.
  • JSON → CSV requires every item to be a flat object or an array; nested objects are stringified rather than exploded into columns.

Frequently asked questions

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