Skip to content
Get packs

CSV to JSON Converter

Data & CSV · Done in 3 steps

Stays on your deviceFree · No sign-up
  1. 1Paste your CSV
  2. 2
  3. 3
Loading tool…

About

Convert CSV to JSON with type detection for numbers, booleans and null, nested objects from dot headers, and objects or arrays output.

How to use it

  1. 1Paste CSV or drop a file; the delimiter and header row are detected.
  2. 2Choose array of objects or array of arrays.
  3. 3Turn type detection and dot-header nesting on or off, and decide what empty cells become.
  4. 4Copy or download the JSON.
You give
CSV/TSV with a header row (or without, using Column N names)
You get
JSON array (pretty-printed or minified)
Good to know
Values with leading zeros and integers beyond 2^53 stay as strings to avoid silent data changes. Dates are kept as strings (JSON has no date type). Files up to roughly 50–100 MB work on a desktop browser (big files are streamed in chunks); phones may run out of memory sooner. The preview shows the first 200 rows, downloads include every row.
Privacy
Processed on your device. Nothing is uploaded, stored or logged.
Last tested
2026-10-28

FAQ

How do I make nested JSON?

Name headers with dots, like address.city and address.zip. With nesting on, they become {"address": {"city": …, "zip": …}}. Numeric parts (tags.0) create arrays.

Why is my zip code still a string?

Values like 02134 would lose their leading zero as a number, so they are deliberately kept as text.

Go further with AI

Prompt · 10 minFree

Structured JSON output

Get valid, schema-shaped JSON from free text every time, with nulls instead of guesses, ready to feed into code or a spreadsheet.

ChatGPT · Claude · Gemini

Prompt · 10 minFree

Research brief builder

Turn a vague topic into a scoped research plan with ranked questions, a source plan and a stop rule before anyone starts searching.

ChatGPT · Claude · Gemini

Prompt · 5 minFree

Meeting notes to action plan

Convert messy notes or a transcript into decisions, an owned action list, open questions and a ready-to-send follow-up email.

ChatGPT · Claude · Gemini

Workflow · 25 minFree

Long-form writing outline

Get from raw notes to a thesis, a section-by-section outline with word budgets and per-section briefs you can draft from.

ChatGPT · Claude · Gemini