A JSON file stores information in a straightforward, readable format that both humans and programs can understand

JSON stands for JavaScript Object Notation. It is a way of organizing data — like names, numbers, addresses, or settings — so that it can be read by different programs and devices. You will not usually create JSON files yourself. Instead, you will encounter them when you export data from one program, back up settings, or read information from a website.

A JSON file looks like plain text with curly brackets and quotation marks. Inside those brackets are pairs of labels and values. For example, a JSON file might say "name": "Sarah" or "age": 28. The label comes first (in quotes), then a colon, then the value. This structure lets any program read the file correctly, even if the program that created it is no longer installed on your computer.

JSON files are common because they are lightweight — they do not take up much storage space — and they work across Windows, Mac, and Linux. If you back up your browser bookmarks, export your contacts from an email program, or read data from a cloud service, you may receive a JSON file.

Key Takeaways

  • JSON files store information in a text format with labels and values separated by colons, making them readable by many different programs.
  • You will most often encounter JSON files when backing up data, exporting settings, or downloading information from websites and online services.
  • JSON files are plain text, so you can open them in any text editor like Notepad or Word to see what is inside.
  • The structure of a JSON file — with curly brackets and quotation marks — allows different programs to read and understand the data correctly.

How JSON files are organized

A JSON file uses a consistent structure so that any program can parse it without confusion. The entire file is wrapped in curly brackets { }. Inside those brackets, information is stored as pairs: a label (called a "key") and a value.

Here is a straightforward example of what a JSON file might contain:

{ "firstName": "James", "lastName": "Rodriguez", "email": "james@example.com", "phone": "555-0147" }

Each label is in quotation marks, followed by a colon, then the value. If you have multiple entries — like a list of contacts — the file will contain multiple sets of brackets, often arranged in an array (a list within square brackets [ ]). The consistent format means a program can find the "email" field in any JSON file, even if it has never seen that particular file before.

Where you will encounter JSON files

JSON files appear in several common situations. When you export your contacts from Gmail, Outlook, or another email service, you often receive a JSON file. When you back up your browser bookmarks from Chrome or Firefox, the backup is usually a JSON file. Many cloud storage services, weather apps, and mapping programs use JSON to exchange data.

If you use a password manager, a budgeting app, or a note-taking service, those programs may let you export your data as JSON. This is useful for backing up your information or moving it to a different program. Social media platforms and online banking sites also use JSON behind the scenes to send information to your device.

You might also receive a JSON file if you read data from a government website, a research database, or an online form. For instance, some genealogy websites let you read family records as JSON files so you can import them into another genealogy program.

How to open a JSON file

Since JSON files are plain text, you can open them with any text editor. On Windows, right-click the JSON file and select Open with, then choose Notepad. On Mac, double-click the file and select TextEdit from the menu that appears. On any system, you can also drag the file into a web browser, and the browser will display the contents in a readable format.

If you want to view a JSON file in a more organized way, you can use a free online JSON viewer. Search for "JSON viewer" in your web browser, then copy and paste the contents of your JSON file into the viewer. It will highlight the structure with colors and indentation, making it easier to understand what information is stored inside.

Do not try to edit a JSON file unless you know what you are doing. The structure — the brackets, colons, and quotation marks — must be exact, or the file will not work when another program tries to read it. If you need to edit a JSON file, make a copy first so you do not damage the original.

JSON versus other file formats

You may also encounter CSV files, XML files, or Excel spreadsheets when backing up or exporting data. Each format has a different purpose. A CSV file (comma-separated values) is simpler and looks like a spreadsheet with rows and columns. An XML file is similar to JSON but uses more text and is older. An Excel file (.xlsx) is a spreadsheet with formulas and formatting.

JSON is preferred for many tasks because it is compact, fast for programs to read, and works well on mobile devices and web browsers. If you are backing up personal data or exporting settings, JSON is often the default option. If you are working with a spreadsheet of numbers or a table of information, CSV or Excel may be more appropriate.

When you export data from a program, that program chooses the format. You do not usually have a choice. However, if a program offers multiple export options, JSON is generally a safe choice because it preserves the structure of your data and works across many different programs.

Keeping your JSON files organized

Since JSON files often contain important data — contacts, bookmarks, settings, or financial records — treat them like any other backup file. Store them in a dedicated folder on your computer, such as Backups or Exports. Label each file with the program it came from and the date you created it, for example: Gmail_Contacts_2024-01-15.json.

Keep at least one copy of important JSON files on an external drive or cloud storage service. If your computer fails, you will still have access to your data. Many people store JSON backups in the same location as other important documents — a cloud folder like Google Drive, OneDrive, or Dropbox.

If you have multiple JSON files from the same program, delete old versions once you confirm the newer one is complete and correct. This prevents confusion and saves storage space. Check the file size: if a JSON backup is much smaller than you expect, it may be incomplete or corrupted.

Frequently Asked Questions

Can I edit a JSON file in Notepad?

Yes, you can open and edit a JSON file in Notepad, but only if you understand the format. Every quotation mark, colon, and bracket must be in the correct place, or the file will not work. If you are not sure what you are doing, make a backup copy first.

What happens if I delete a JSON file by accident?

If you have a backup copy on an external drive or cloud storage, you can restore it. If not, the file is usually gone. This is why storing JSON backups in multiple locations is important. Some cloud services keep deleted files in a trash folder for 30 days.

Do I need special software to open a JSON file?

No. Any text editor works, and most web browsers can display JSON files. If you want a more organized view, use a free online JSON viewer. You do not need to purchase anything.

Why is my JSON file so large?

JSON files can be large if they contain a lot of data — thousands of contacts, years of messages, or detailed records. If a file seems unusually large, check that it is not corrupted or that you did not accidentally export more data than intended.

Can I import a JSON file into a different program?

Sometimes. Many programs let you import JSON files, but not all do. Check the program's documentation or settings menu for an import option. If the program does not support JSON, you may need to convert the file to a different format first.