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Data helper

CSV ⇔ JSON Converter

Convert between CSV and JSON formats seamlessly.
Support for custom delimiters (comma, tab, semicolon) and bidirectional conversion.
Perfect for data migration, spreadsheet integration, and quick data analysis.

Guide: How to use & features

  • Select the conversion direction: CSV to JSON or JSON to CSV.
  • Under "Options," specify the delimiter (comma, tab, or semicolon) for your data.
  • Paste your data into the input field to see the conversion results instantly.
  • Click "Copy Output" to grab the converted data for your project.

Samples: Sample input & output

CSV to JSON conversion

Input

id,name,role
1,Alice,Admin
2,Bob,User

Output

[
  {
    "id": "1",
    "name": "Alice",
    "role": "Admin"
  },
  {
    "id": "2",
    "name": "Bob",
    "role": "User"
  }
]

JSON to CSV conversion

Input

[
  {"id": 1, "product": "Widget", "price": 10.5},
  {"id": 2, "product": "Gadget", "price": 20.0}
]

Output

id,product,price
1,Widget,10.5
2,Gadget,20

FAQ: FAQ

  • How is nested JSON (nested objects or arrays) converted?

    CSV is a flat table of rows and columns, so nested structures cannot be represented as-is. Data shaped as an array of objects where each item shares the same keys converts most cleanly. For deeply nested data, flatten the fields you need to the top level first for stable results.

  • Can I choose the delimiter and whether there is a header row?

    Yes — it supports comma, tab, and semicolon delimiters and lets you toggle a header row. Tab (TSV) or semicolon delimiters can work better with Excel in locales that use a comma as the decimal separator.

  • Non-ASCII text looks garbled when I open the file in Excel — what should I do?

    That happens because Excel does not auto-detect UTF-8; the converted data itself is correct. Import via Data → From Text/CSV in Excel and choose UTF-8 as the encoding to open it without garbled characters.

Use cases: Common use cases

  • Convert Spreadsheet Data to JSON

    Convert table data copied from Excel or Google Sheets into JSON format for use as initial program data or mock APIs.

  • Export API Responses to CSV

    Convert JSON data received from an API to CSV for easier aggregation and analysis in spreadsheet software.

  • Data Format Conversion & Cleansing

    Switch between CSV and JSON while easily changing delimiters (comma/tab) to normalize your data formats.

Notes: Notes & limitations

  • Nested Structures

    When converting JSON to CSV, nested objects or arrays are not flattened. Plain, flat JSON structures are recommended.

  • Large Datasets

    Converting extremely large datasets may cause the browser to freeze or crash due to memory limitations.

CSV and JSON Converter

CSV and JSON are common data exchange formats, but they serve different workflows. This converter helps turn CSV rows into JSON objects and flatten simple JSON data into CSV for spreadsheets, tests, API fixtures, and quick data handoffs.

Common use cases

  • Create API fixtures: Convert spreadsheet exports into JSON samples for tests or mock servers.
  • Prepare spreadsheet data: Turn simple JSON records into CSV for analysis or sharing.
  • Inspect data shape: Check fields, values, and inferred types before importing data elsewhere.

Conversion note

CSV is flat, while JSON can be nested. Arrays and nested objects need a flattening or serialization convention before they can fit cleanly into columns.

Articles for this tool

Introduction
2026-05-02

CSV and JSON Conversion: Choosing the Right Format for APIs and Data Migration

Learn how to convert between CSV and JSON safely, including headers, delimiters, value types, nested data, and practical workflow tips.

Recent Articles

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How CREATE TABLE Generation From a Visual Table Design Works | DDL Builder

A look inside DDL Builder, which turns a visually designed table into CREATE TABLE statements and an ER diagram. Covers the MySQL/PostgreSQL/SQLite type-mapping rules and the column-inference algorithm used for JSON samples.

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2026-07-21

GitHub Actions needs Design Patterns: Speed Up CI, Avoid the Anti-Patterns

A pattern reference for GitHub Actions job dependencies (needs). Covers diamond-shaped fan-out, concurrency cancellation, fail-fast tradeoffs, matrix-plus-needs gotchas, and reusable workflows, with copy-paste YAML examples.

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2026-07-21

SQL JOIN Types: Complete Reference to INNER, LEFT, RIGHT & FULL

A reference for SQL JOIN types (INNER/LEFT/RIGHT/FULL/CROSS/SELF) with a cheat sheet and row-count walkthroughs. Covers why one-to-many joins duplicate rows, the WHERE-vs-ON NULL trap, and how to write multi-table joins.

Introduction
2026-07-16

Case Converter: camelCase, snake_case & kebab-case — 9 Styles at Once

Convert identifiers between camelCase, PascalCase, snake_case, CONSTANT_CASE, kebab-case and more — all nine styles side by side. Handles acronym runs like HTTPServer, digits, and bulk multi-line conversion.

Introduction
2026-07-16

LLM API Cost Calculator: Compare Claude, GPT & Gemini Pricing Side by Side

Paste a prompt, set the expected output tokens, and compare per-request API costs across Claude, GPT and Gemini models. Covers input/output pricing structure, auto-updated price tables, and estimate limits.

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2026-07-14

AGENTS.md, CLAUDE.md, Cursor Rules: One Source of Truth for AI Coding Agents

Every AI coding agent wants its own rules file. Compare AGENTS.md, CLAUDE.md, .cursor/rules, copilot-instructions.md and more — what to write, a copy-paste template, and how to stop them drifting apart.

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