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JSON Tasks Every Developer Does — And the Fastest Way to Do Each One

#json #webdev #productivity #beginners

Task 1: Format a Minified JSON Response

The situation: You curl an API endpoint and get back one long line of JSON. You need to read it.

curl https://api.example.com/users/1
# {"id":1,"name":"Alice","email":"alice@example.com","address":{"city":"Berlin","zip":"10115"},"tags":["admin","user"],"active":true}
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The fast way:

  1. Paste into JSON Buddy
  2. Press Ctrl+Enter to format 
{
  "id": 1,
  "name": "Alice",
  "email": "alice@example.com",
  "address": {
    "city": "Berlin",
    "zip": "10115"
  },
  "tags": ["admin", "user"],
  "active": true
}
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The editor also shows you the size, key count, and depth of the JSON in the header stats. Syntax errors are highlighted at the exact character position.

Reverse direction: Need to minify JSON before sending it? Ctrl+Shift+Enter.

Task 2: Write a Typed Model for an API Response

The situation: You're integrating an API and need to write a Go struct, TypeScript interface, or Python dataclass to represent the response.

The JSON has 15 fields, some nested. You could type it by hand, but you'll probably miss a field or get a type wrong.

The fast way:

  1. Paste the JSON into JSON Buddy
  2. Click Code Gen in the toolbar
  3. Select your language (Go, TypeScript, Java, Python, Rust, C#, PHP, Ruby, C, C++, Zig)
  4. Copy the output

For the user JSON above, selecting Go gives:

type Root struct {
    Id      int64    `json:"id"`
    Name    string   `json:"name"`
    Email   string   `json:"email"`
    Address Address  `json:"address"`
    Tags    []string `json:"tags"`
    Active  bool     `json:"active"`
}

type Address struct {
    City string `json:"city"`
    Zip  string `json:"zip"`
}
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Nested objects become separate structs automatically. Types are inferred from values.

More details: JSON to Struct Generator

Task 3: Convert Spreadsheet Data to JSON

The situation: A PM sends you a .xlsx file with test users. Your seed script expects JSON. You need to convert it without writing a pandas script.

The fast way:

  1. Click CSV/Excel to JSON in the toolbar
  2. Upload the .xlsx or paste copied table data from Excel/Google Sheets
  3. Copy the JSON output 
name    age    city      role
Alice   30     Berlin    admin
Bob     25     Paris     user
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Converts to:

[
  { "name": "Alice", "age": 30, "city": "Berlin", "role": "admin" },
  { "name": "Bob",   "age": 25, "city": "Paris",  "role": "user" }
]
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Types are inferred: numbers stay numbers, booleans stay booleans. No manual post-processing needed.

More details: CSV to JSON Converter

Task 4: Bulk Replace Values Before Sharing

The situation: You want to share a JSON fixture with a colleague, but it has real email addresses and internal URLs that shouldn't be shared.

The fast way:

  1. Press Ctrl+F in the JSON editor
  2. Enable wildcard mode (.* button)
  3. Search *@*.com → Replace All → [redacted]
  4. Search https://internal.api.company.com → Replace All → https://api.example.com
  5. Done

The find & replace bar shows a live match counter (3/8) and highlights every match as you type.

More details: JSON Find & Replace

Task 5: Debug a JSON Syntax Error

The situation: JSON.parse() throws SyntaxError: Unexpected token } in JSON at position 847. You have no idea where character 847 is.

The fast way:

Paste the JSON into JSON Buddy. The editor jumps to the error position and shows a banner at the bottom:

Syntax Error
Unexpected token '}' at position 847
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The offending line is highlighted in red. Common causes caught immediately:

  • Trailing commas (invalid in JSON, common from copy-pasting JS objects)
  • Unquoted keys ({name: "Alice"} instead of {"name": "Alice"})
  • Single-quoted strings
  • Missing commas between fields
  • Comments (// ... or /* ... */ — not valid JSON)

The Format button (Ctrl+Enter) also applies heuristic fixes to invalid JSON where possible — useful for recovering a JS object literal as valid JSON.

Bonus: Load JSON from a URL

Need to inspect a public API response directly? Click the link icon in the toolbar, paste the URL, and the response is fetched and loaded into the editor. Useful for checking /.well-known/ files, inspecting GitHub API responses, or validating a public config endpoint.

Why One Tool for All of This?

Having these tasks in a single tool means:

  • No context-switching between five different websites
  • Consistent keyboard shortcuts (Ctrl+Enter, Ctrl+F, etc.)
  • No data leaving your browser — everything is local
  • Works offline after first load (PWA)
  • History of your last 50 JSON snippets, stored in localStorage

Summary

Task How to do it
Format JSON Paste → Ctrl+Enter
Validate & find errors Paste → see highlighted error position
Generate struct/class Paste → Code Gen → pick language → Copy
CSV/Excel → JSON CSV tab → upload or paste
Find & replace Ctrl+F → search → Replace All
Load from URL Toolbar link icon → paste URL

👉 json-formatter.net — free, no sign-up, no uploads, works offline.

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