How to Read a JSON File Using Python

JSON (JavaScript Object Notation) has become one of the most popular data formats for exchanging information between a client and server. It is lightweight, easy to read, and supported by almost every modern programming language — including Python.

If you're a developer working with Python in 2025, mastering how to read JSON files efficiently is crucial. In this article, we will guide you step-by-step on reading JSON files using Python code, the latest practices, and how tools like a json formatter, json formatter online, and online json formatter can help you easily visualize and debug your JSON data.

Let's dive deep into JSON, learn to format json, and make the most out of your Python programming skills!

What is JSON?

JSON stands for JavaScript Object Notation. It's a way of structuring data that is easy for humans to read and write and easy for machines to parse and generate.

Here’s a simple example of a JSON object:

{
  "name": "John",
  "age": 30,
  "city": "New York"
}

This structure is intuitive, making JSON the preferred choice for data interchange, APIs, and configuration files.

When working with JSON data, you might need a json formatter or a json formatter online tool to properly format and validate your JSON structure. These tools ensure your JSON is clean, readable, and free from errors.

Why Read JSON Files in Python?

Python’s json library makes reading JSON files straightforward.

Whether you're handling API responses, configuration settings, or working on data analysis, you’ll frequently come across JSON files.

You may want to:

• Read configuration settings
• Process API responses
• Analyze datasets
• Migrate data
• Debug applications

No matter the case, understanding how to read JSON files correctly in Python is fundamental.

How to Read a JSON File Using Python

Python provides built-in support through its json module.

Here's a simple guide to reading a JSON file:

1. Import the JSON module

import json

2. Open the JSON file

You must open the JSON file using Python’s open() function.

with open('data.json', 'r') as file:
    data = json.load(file)
    print(data)

• open('data.json', 'r') opens the file in read mode.
• json.load(file) parses the file content into a Python dictionary.

Example: Read JSON File in Python

Assume we have a file called employee.json:

{
  "id": 101,
  "name": "Alice",
  "department": "HR",
  "salary": 50000
}

Python code to read this file:

import json

with open('employee.json') as f:
    employee_data = json.load(f)
    print(employee_data)

Output:

{'id': 101, 'name': 'Alice', 'department': 'HR', 'salary': 50000}

Simple, isn’t it?

Prompt User to Enter JSON File Name

In 2025, applications are becoming increasingly interactive.

You might want the user to input the JSON filename at runtime instead of hardcoding it.

Here’s how to prompt the user for the file name:

import json

filename = input("Enter the name of the JSON file (with extension): ")

try:
    with open(filename, 'r') as file:
        data = json.load(file)
        print("JSON Data Loaded Successfully!")
        print(data)
except FileNotFoundError:
    print("File not found. Please check the file name.")
except json.JSONDecodeError:
    print("Invalid JSON format.")

What's Happening Here?

• input() prompts the user for a filename.
• A try-except block handles errors gracefully.
• If the file doesn't exist or JSON is invalid, the program informs the user.

Validate and Format JSON Online

When working with JSON, sometimes you encounter poorly formatted or minified JSON.

This is where a json formatter online or an online json formatter becomes very helpful.

Tools like jsonformatter or json online formatter allow you to:

• Paste your JSON code
• Format JSON neatly
• Validate JSON structure
• Identify syntax errors instantly

If you are stuck with a messy JSON file, use a json formater tool online to beautify your data.

Best Online JSON Formatter Tools in 2025

Here’s a list of popular json formatter online tools you can rely on:

1. JSONFormatter.org – Easy formatting, validation, and beautification.
2. OnlineJSONFormatter.com – Advanced features like tree view and error detection.
3. FreeCodeTools JSON Formatter – Lightweight and free JSON beautifier.
4. CodeBeautify JSON Formatter – A trusted online json formatter with robust features.

These tools allow you to quickly format, validate, and debug your JSON files before loading them into Python.

How to Format JSON Data in Python

Apart from using an online json formatter, you can also format JSON data directly within Python.

Pretty Print JSON

If you want your JSON output to look clean and readable:

import json

with open('employee.json') as f:
    data = json.load(f)

pretty_json = json.dumps(data, indent=4)
print(pretty_json)

The indent=4 parameter adds indentation to each level.

Output:

{
    "id": 101,
    "name": "Alice",
    "department": "HR",
    "salary": 50000
}

You can now easily read and understand your data without any confusion!

How to Read Nested JSON Files

Sometimes JSON files are deeply nested. Let’s say your JSON looks like this:

{
  "company": {
    "name": "TechSoft",
    "location": "USA",
    "employees": [
      {"id": 1, "name": "John"},
      {"id": 2, "name": "Emma"}
    ]
  }
}

To read nested data:

import json

with open('company.json') as f:
    data = json.load(f)

print(data['company']['name'])       # Output: TechSoft
print(data['company']['employees'])  # List of employees

Navigating through nested structures is simple in Python using keys and indexes.

Reading JSON String Instead of File

Sometimes, you receive JSON data as a string from an API instead of a file.

Here's how to handle it:

import json

json_string = '{"name": "Robert", "age": 29, "city": "San Francisco"}'
data = json.loads(json_string)

print(data)

• json.loads() loads JSON data from a string.
• json.load() loads JSON data from a file.

Both are important depending on your situation.

Common Errors When Reading JSON Files

While reading JSON files, you might encounter:

Tips to Avoid Errors:

• Always validate JSON using a json formatter before loading.
• Use try-except blocks.
• Ensure the file path is correct.

Conclusion

In 2025, working with JSON files is more crucial than ever for Python developers.

Knowing how to read JSON files using Python code empowers you to handle APIs, databases, configurations, and much more.

Using built-in Python modules combined with tools like an online json formatter, json formatter online, or json online formatter will help you work faster and more efficiently.