JSON Quick Start Guide

From raw JSON to CSV, Excel, or Markdown. Covers data types, nested JSON, JSON Path, NDJSON, export formats, and troubleshooting.

Table of Contents

1. JSON Basics

JSON (JavaScript Object Notation) is a lightweight text format for storing and exchanging data.

[
  { "name": "Alice", "age": 30, "active": true },
  { "name": "Bob",   "age": 25, "active": false }
]

5 Data Types at a Glance

Type	Example	Notes
String	"hello"	Double quotes required. No single quotes.
Number	42, 3.14, -7	Integers and decimals. No quotes.
Boolean	true, false	Lowercase. No quotes.
Null	null	Represents "no value". Lowercase.
Array	[1, "a", null]	Ordered list. Items can be any type.
Object	{"key": "value"}	Key-value pairs. Keys are strings.

Key Syntax Rules

• Strings use double quotes — "hello" is valid, 'hello' is not.
• Objects use curly braces: {...}
• Arrays use square brackets: [...]
• Trailing commas are not allowed: {"a":1,} is invalid.
• Dates are stored as strings: "2026-06-03" (ISO 8601).
• Unicode escape: "\u4e2d" = "中"

2. JSON vs CSV vs XML vs YAML

JSON sits in a unique position among data formats. Here's how it compares:

3. Real-World JSON Formats

API Response (Wrapped Object)

Most APIs wrap their data in an outer object with metadata:

{
  "status": "ok",
  "count": 2,
  "data": {
    "users": [
      { "id": 1, "name": "Alice", "email": "alice@example.com" },
      { "id": 2, "name": "Bob",   "email": "bob@example.com" }
    ]
  }
}

How to handle: JSON Path = data.users

Common API wrapping patterns:

API Source	Pattern	JSON Path
GitHub API	{"data":{"nodes":[...]}}	data.nodes
REST API	{"results":[...]}	results
Paginated API	{"data":{"list":[...],"total":100}}	data.list
GraphQL	{"data":{"users":[...]}}	data.users

NDJSON / JSON Lines

One JSON object per line. Common in logs and streaming data:

{"ts":"2026-06-03T10:00:00Z","level":"info","msg":"Server started"}
{"ts":"2026-06-03T10:00:01Z","level":"warn","msg":"Memory at 85%"}
{"ts":"2026-06-03T10:00:02Z","level":"error","msg":"Connection refused"}

JSONXX auto-detects NDJSON. Each line becomes a row. Blank lines are ignored.

Common sources: Docker logs, Kafka messages, database exports, Elasticsearch bulk API.

Nested Object (Database Export)

{
  "orderId": 1001,
  "customer": { "name": "Alice", "tier": "gold" },
  "items": [
    { "sku": "A1", "name": "Widget", "qty": 2, "price": 9.99 },
    { "sku": "B2", "name": "Gadget", "qty": 1, "price": 24.50 }
  ]
}

Use dot-separated mode to flatten customer.name and customer.tier into separate columns.

Single Object vs Array

Format	Example	How JSONXX Handles It
Array (standard)	[{...}, {...}]	Converts directly to table
Single object	{"name":"Alice"}	Wraps as 1 row automatically
API wrapped	{"data":[{...}]}	Use JSON Path to extract
NDJSON	{...}\n{...}	Auto-detects line-by-line

4. Nested JSON & Flattening

When JSON has objects inside objects, you need to flatten them into a flat table. JSONXX offers three modes.

Input:

[
  { "name": "Alice", "address": { "city": "Beijing", "district": "Haidian" } },
  { "name": "Bob",   "address": { "city": "Shanghai", "district": "Pudong" } }
]

Mode 1: Dot-separated (Default)

name	address.city	address.district
Alice	Beijing	Haidian
Bob	Shanghai	Pudong

Best for: flat tables, data analysis, CSV export.

Mode 2: JSON String

name	address
Alice	{"city":"Beijing","district":"Haidian"}
Bob	{"city":"Shanghai","district":"Pudong"}

Best for: preserving nested structure in a single cell.

Mode 3: 1-Level Only

name	city	district
Alice	Beijing	Haidian
Bob	Shanghai	Pudong

Best for: when only the first nesting level matters.

Deep Nesting (3+ Levels)

Dot-separated flattens to the deepest level automatically:

{ "user": { "profile": { "address": { "city": "Beijing" } } } }

Result column: user.profile.address.city

5. JSON Path Reference

JSON Path tells the tool exactly where your data is. Leave it empty for auto-detect.

Common Patterns

Scenario	JSON Path
Root-level array	(leave empty)
{"data": [...]}	data
{"data": {"items": [...]}}	data.items
{"result": {"records": [...]}}	result.records
Nested API (3 levels)	response.data.users

Supported Syntax

# Dot notation (recommended)
data.items

# Bracket notation (for special characters)
['data']['user-list']
['results'][0]['items']

# Mixed notation
data['user-list'].items

When Do You Need JSON Path?

Situation	Need Path?
JSON is a root-level array [...]	No
JSON is a single object {...}	No
JSON is API-wrapped {"data":[...]}	Yes
Auto-detect picked the wrong array	Yes
Multiple arrays, need a specific one	Yes

6. Export Format Guide

CSV (.csv)

Excel (.xlsx)

Markdown (.md)

TSV (Clipboard)

Which Format Should I Choose?

Your Need	Recommended
Not sure	CSV (most universal)
Excel user	.xlsx (no encoding risk)
GitHub docs	Markdown
Quick paste to Excel	Copy TSV
Database import	CSV (UTF-8)
Chinese data	CSV UTF-8 BOM or .xlsx

7. Editing & Shortcuts

The table is fully editable — not just a preview. Fix values before exporting.

Keyboard Shortcuts

Shortcut	Action
Double-click	Edit cell
Tab	Confirm edit, move right
Enter	Confirm edit, move down
Escape	Cancel edit
Ctrl+Z / Cmd+Z	Undo (up to 50 steps)
Ctrl+Y / Cmd+Y	Redo
Delete	Clear selected cell

Right-Click Context Menu

Column Operations

Operation	How
Sort	Click column header to toggle asc/desc
Hide column	Right-click header → Hide Column
Unhide columns	Right-click any header → Unhide Columns

Live Preview vs Blind Export

Traditional Tools	JSONXX
Paste → Export → Download	Paste → See table → Edit → Export
Discover errors after export	Fix before exporting
Can't modify data	Double-click any cell to edit

8. Troubleshooting

Table is Empty

Wrong Data Shown

Excel Shows Garbled Text

File Too Large

NDJSON Not Detected

Columns Missing

Frequently Asked Questions

Ready to Try It?

Open the JSON to CSV tool and paste your data.

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