# 10 JSON Mistakes Every Developer Makes (And How to Avoid Them)

fati_theDev — Wed, 01 Jul 2026 10:48:15 +0000

JSON is everywhere.

Whether you're building REST APIs, working with configuration files, or integrating third-party services, chances are you're dealing with JSON every day.

After building several online developer tools for formatting, validating, comparing, and converting JSON, I've noticed the same mistakes appear over and over again.

Here are the ten most common ones—and how to avoid them.

1. Using Single Quotes Instead of Double Quotes

❌ Invalid

{
  'name': 'John'
}

✅ Valid

{
  "name": "John"
}

JSON only accepts double quotes for property names and string values.

2. Leaving a Trailing Comma

❌

{
  "name": "John",
  "age": 25,
}

✅

{
  "name": "John",
  "age": 25
}

Many languages allow trailing commas, but JSON does not.

3. Forgetting to Escape Special Characters

Incorrectly escaped strings often cause parsing failures.

Example:

{
  "message": "He said \"Hello\""
}

4. Mixing Data Types

Avoid this:

{
  "price": "100",
  "stock": 50
}

If price is numeric, keep it numeric.

{
  "price": 100,
  "stock": 50
}

Consistent data types make your APIs much easier to consume.

5. Making JSON Hard to Read

This:

{"id":1,"name":"Laptop","price":1200}

is valid, but difficult to debug.

Pretty-printing JSON saves time when troubleshooting.

6. Deeply Nested Objects

Large nested structures become difficult to maintain.

Instead of nesting everything inside multiple objects, consider flattening your data model where it makes sense.

7. Duplicate Keys

{
  "name": "Alice",
  "name": "Bob"
}

Most parsers keep only the last value, which can introduce subtle bugs.

8. Ignoring Validation

Never assume JSON coming from users or external APIs is valid.

Always validate before processing.

9. Not Comparing API Responses

When debugging APIs, it's often helpful to compare two JSON responses side by side to quickly identify changes instead of inspecting hundreds of lines manually.

10. Reformatting JSON Manually

Indentation issues waste time.

Use a formatter instead of editing whitespace yourself.

Helpful Tools

If you're looking for free browser-based tools, I've built a collection that can help with everyday development tasks, including:

JSON Formatter & Validator
JSON Compare
JSON to TypeScript
Base64 Encoder & Decoder
CSS Formatter
JavaScript Obfuscator
Box Shadow Generator
Zakat Calculator

You can try them here:

https://devtoolsworld.com

No signup is required, and everything runs directly in your browser.

Final Thoughts

JSON looks simple, but small mistakes can lead to frustrating bugs.

Using validation, formatting, and comparison tools can save a surprising amount of debugging time—especially when working with APIs every day.

What JSON mistake has cost you the most time? Share it in the comments.

I Got Tired of Slow, Ad-Filled Dev Tools — So I Built My Own

fati_theDev — Tue, 05 May 2026 08:31:43 +0000

As developers, we use online tools all the time — JSON formatters, CSS generators, minifiers, validators…

But honestly, most of them feel like this:

painfully slow
overloaded with ads
forcing logins for basic features

After a while, it just gets frustrating.

So instead of complaining, I decided to build my own.
⚡ The Goal

I didn’t want to create just another tool website.

I focused on three simple things:

Speed – everything should feel instant
Clean UI – no clutter, no distractions
No login required – open and use, that’s it
🛠️ What I Built

I started with a small set of tools that I personally use daily:

JSON Formatter & Validator
CSS Generators (Box Shadow, Gradients, etc.)
Minifiers & Beautifiers

Nothing revolutionary — just fast, clean, and usable.
🚫 What I Avoided (On Purpose)

This part mattered the most to me.

I deliberately avoided:

intrusive ads everywhere
popups asking for signups
locking basic features behind paywalls

Because let’s be honest — dev tools should save time, not waste it.

💡 What I Learned

Building this made me realize something:

Developers don’t need more tools — they need better ones.

Even small improvements like:

faster response time
fewer clicks
cleaner layout

…make a huge difference in daily workflow.

🌍 Why I’m Sharing This

I’m not trying to “sell” anything here.

I genuinely want feedback from other developers:

What tools do you use most?
What annoys you about existing ones?
What should I build next?
🔗 Try It Out

If you’re curious, you can check it out here:
👉 https://devtoolsworld.com/

I’d really appreciate honest feedback — even harsh criticism is welcome.

🚀 What’s Next

I’m planning to:

add more developer utilities
improve performance further
keep everything simple and accessible

If you’ve ever felt frustrated with online dev tools, I’d love to hear your experience.

What’s the one tool you wish existed but doesn’t?
🧠 I Want Honest Opinions

If you disagree with me, even better.

Are dev tools actually fine as they are?
Am I overreacting?
What’s the worst tool experience you’ve had?

DEV Community: fati_theDev