Convert CSV to JSON Online — SQL-Powered, In-Browser

Need to turn a CSV into JSON for an API, a config file, or a frontend fixture? PondPilot converts CSV to JSON directly in the browser, with SQL in between so you can filter and reshape before export.

How to Convert

  1. Open app.pondpilot.io
  2. Drop in your .csv file
  3. Query and reshape with SQL
  4. Export as JSON

Everything runs locally via DuckDB WebAssembly. No server, no upload.

Filter Rows Before Exporting

Most CSV-to-JSON tools dump every row. That’s rarely what you want — JSON payloads are read by humans and machines that care about size.

SELECT id, name, email
FROM read_csv_auto('contacts.csv')
WHERE subscribed = true
  AND email IS NOT NULL

Export only the rows and columns you actually need.

Build Nested Structures

JSON isn’t flat. DuckDB lets you construct nested objects and arrays on the way out:

SELECT
  user_id,
  {'first': first_name, 'last': last_name} AS name,
  list(tag) AS tags
FROM read_csv_auto('users.csv')
GROUP BY user_id, first_name, last_name

Turn a flat CSV into a JSON shape that matches your API contract.

NDJSON or JSON Array

Export as a standard JSON array or as newline-delimited JSON (NDJSON), whichever your downstream tool expects. NDJSON is nicer for streaming and log pipelines.

Privacy

CSVs exported from CRMs, analytics tools, or internal dashboards often contain names, emails, and account data. PondPilot processes everything in-browser, so nothing is uploaded.

Get Started

Visit app.pondpilot.io and convert your CSV to JSON.

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