How do I convert CSV to JSON?

Paste your CSV data (with headers in the first row) and click Convert. Each row becomes a JSON object, with column headers as keys. The output is a JSON array of objects.

Does the CSV need headers?

Yes, the first row should be column headers. These become the JSON property names. If your CSV has no headers, add them manually before converting.

How are data types handled?

Numbers are automatically converted to numeric types, "true"/"false" become booleans, and empty cells become null. Everything else stays as a string.

Can I convert TSV (tab-separated values)?

Currently the tool expects comma-separated values. For TSV data, do a quick find-and-replace to change tabs to commas first, then paste into the converter.

CSV → JSON

CSV を構造化 JSON に変換

CSV入力

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JSON出力

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Turn spreadsheet exports into structured JSON

CSV is everywhere — exports from databases, CRMs, analytics tools, and finance systems all show up as comma-separated rows. Converting that into JSON gives you keyed objects, proper data types for numbers and booleans, and an array shape that fits naturally into APIs, app state, and database imports.

Use the converter when you need to

Feed a CSV export into an API

Transform a dataset from analytics or finance into JSON so you can POST it to an internal service or webhook.

Seed test data for an app

Take a sample CSV and produce a JSON array you can drop into fixtures, mock servers, or local databases.

Hand a dataset to a frontend developer

JSON arrays are easier to consume in JavaScript than parsing CSV by hand — convert once, ship the JSON.

How to convert CSV to JSON quickly

1
Paste your CSV (with headers in the first row) into the editor.
2
Click Convert to map each row to a JSON object using header names as keys.
3
Copy the JSON output or download it for direct use in your app.

Keep going

Convert JSON back to CSV

Round-trip the data when a downstream consumer needs CSV instead.

Format the JSON output

Beautify the converted JSON before pasting into code or a request body.

Validate the result

Confirm the converted JSON parses cleanly before sending it to an API.

Explore the converted data

Use the tree view to make sure nested fields and types look right.

Common CSV-to-JSON workflows

Migrate spreadsheet data into an app

Convert a one-off CSV export from a colleague into JSON your code can consume directly.

Build mock fixtures from real data

Take production CSV exports and turn them into JSON fixtures for local dev and tests.

Bulk-create records via API

Convert a CSV of customers, products, or events into JSON your batch endpoint can ingest.

よくある質問

CSVデータ（1行目がヘッダー）を貼り付けて「Convert」をクリックします。各行がJSONオブジェクトになり、ヘッダーがキーとして使われます。出力はオブジェクト配列のJSONです。

はい。1行目は列ヘッダーにしてください。これがJSONのプロパティ名になります。ヘッダーがないCSVの場合は、変換前に手動で追加してください。

数値は自動的に数値型へ変換され、"true"/"false" はbooleanになります。空セルはnullになります。それ以外は文字列のままです。

現在はカンマ区切りを前提としています。TSVは、タブをカンマに置換してからコンバーターに貼り付けてください。