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TSV to JSON Converter

Turn tab-separated data into a JSON array of objects: header cells become keys, numbers and booleans become real JSON values, and leading-zero codes stay strings.

Quick presets

First row is the header Detect numbers & booleans Nest dotted headers (a.b)

Indent

TSVOpen file

JSON

Table preview –

Runs in your browser — nothing you enter is uploaded or stored.

ToolFeather · TSV → JSON

Scratchpad auto-saved

Stored in this browser (localStorage)

Step-by-step~40s read

How it works — in four simple steps

No signup and nothing to install — it all runs in your browser.

Add your TSV

Paste it into the left box, press Open file, or drag a .tsv file onto it. Sample loads a realistic example.

Set the options

Adjust the options above the boxes — the output updates instantly as you change them.

Check the result

Read the status line: it reports rows, keys and any value that couldn't be represented in JSON.

Copy or download

Copy the JSON or download it as a .json file. Nothing was uploaded at any point.

Pro tip

Store codes like 00142 stay strings, so leading zeros are never lost.

Features

Header row or not

Use the first row as field names, or treat every row as data with generated column1, column2… names.

Real types, not just strings

Numbers, booleans and empty values are detected — while codes with leading zeros such as 00742 or +44 phone numbers stay text.

Rebuild nested objects

Headers like address.city can be folded back into nested objects instead of flat dotted keys.

Pretty or minified

2 or 4 spaces, tabs, or a minified single line for the smallest possible file.

Private by design

Parsing and conversion run in your browser with JavaScript — your data is never uploaded, logged or stored.

About the TSV to JSON Converter

TSV shows up whenever data comes off a clipboard or a database dump, and JSON is what APIs, JavaScript and NoSQL databases want. The conversion is row-to-object: the first line supplies the keys, and each following line becomes one object with a value per key.

With Detect numbers & booleans on, 42 and 3.5 become JSON numbers, true/false become booleans, and empty cells become null. Values that only look numeric — 00742, +44 20 7946 0958, a 16-digit card-style ID — stay strings, because converting them would corrupt them. Tick Nest dotted headers to turn geo.lat and geo.lng columns into a nested geo object.

If there's no header row, untick First row is the header and keys are generated as column1, column2… The JSON can be pretty-printed with 2 or 4 spaces or tabs, or minified for transport.

Examples

A store list exported from a database as TSV, with a leading-zero store code and dotted coordinate headers.

TSV input

code	city	geo.lat	geo.lng	open
00142	Pune	18.5204	73.8567	true
00217	Mumbai	19.0760	72.8777	true
00305	Nashik	19.9975	73.7898	false

JSON output

[
  {
    "code": "00142",
    "city": "Pune",
    "geo": {
      "lat": 18.5204,
      "lng": 73.8567
    },
    "open": true
  },
  {
    "code": "00217",
    "city": "Mumbai",
    "geo": {
      "lat": 19.076,
      "lng": 72.8777
    },
    "open": true
  },
  {
    "code": "00305",
    "city": "Nashik",
    "geo": {
      "lat": 19.9975,
      "lng": 73.7898
    },
    "open": false
  }
]

This output was produced by the converter on this page with Nest dotted headers switched on — load it with the “Store list” preset above and change any option to see the effect.

How TSV maps to JSON

In TSV	Becomes in JSON
Header row	object keys
Each line	one object in the array
`98.5`, `true`	`98.5`, `true`
`00742`	`"00742"`
Empty field	`null`
`geo.lat` + Nest	`"geo": {"lat": …}`

Things that trip people up

Header with spaces. Keys are kept exactly, so First Name becomes the key "First Name". Rename headers first if your code expects first_name.
Duplicate headers. JSON objects can't hold two equal keys — the later column wins. Rename duplicates before converting.
Big integers. Integers with 16 or more digits are kept as strings so JavaScript doesn't round them.
Dates. Dates stay strings (JSON has no date type); parse them in your code.

TSV vs JSON at a glance

Property	TSV	JSON
Specification	IANA text/tab-separated-values	RFC 8259 (2017) · ECMA-404
File extension	.tsv / .tab	.json
Media type	text/tab-separated-values	application/json
Data types	text only	string, number, boolean, null, object, array
Comments	No	No
Nesting	None (flat rows)	Unlimited

TSV: The IANA definition has no quoting at all: a field simply may not contain a tab or a line break.
JSON: Numbers are parsed as IEEE-754 doubles in JavaScript, so integers above 9,007,199,254,740,991 (2⁵³ − 1) lose precision.

Frequently asked questions

5 answers

How do I convert tab-delimited text to JSON?

Paste it or open the .tsv file; each line becomes an object keyed by the header row, and the JSON updates as you type.

Are numbers converted to JSON numbers?

Yes, with Detect numbers on. Values with leading zeros, phone numbers and very long IDs stay strings so they aren't changed.

What if my file has no header row?

Untick First row is the header; keys are generated as column1, column2 and so on.

Can I get minified JSON?

Yes — choose minified in the Indent option for a single-line result.

Is my data uploaded anywhere?

No. The TSV is parsed and converted by JavaScript in your browser tab; nothing is sent to a server, so it is safe for internal exports, customer lists and configuration files with secrets.