As you may have noticed, people often compare XML and JSON – and even argue over which is better. That is mainly because both tend to be used for a very similar purpose: To store and organize data in a readable format, and facilitate its transfer.

However, even though they have a similar use – XML and JSON actually have many key differences. And to understand those differences you first need to know what XML and JSON really are.

What is XML?

XML is a markup language, and is an abbreviation for ‘Extensible Markup Language’. It was derived from a previous markup language known as SGML and was first released in 1998.

As a markup language, XML is designed to carry data and organize it using tags to define elements. It is known as ‘extensible’ because it allows you to create descriptive tags of your own and is language-independent (meaning it can be used with any programming language).

It should be noted that XML is not a programming language on its own, and cannot process data using algorithms or computation. All it can do is capture, store, and organize data.

What is JSON?

Unlike XML, JSON is not a markup language but a data format instead. It was originally designed to store structured data to be used in JavaScript – which is why its name stands for ‘JavaScript Object Notation’.

Despite being created for JavaScript, the JSON format is language-independent and can be used with other programming languages. Initially it owed a lot of its popularity to the fact that JavaScript was so widely used, but now it stands firmly on its own two feet.

Just like XML, JSON is not a programming language. In fact, it is not even a markup language and does not have descriptive tags either.

Differences Between XML and JSON

By this point, you’ve probably noticed the main key difference between XML and JSON: XML is a markup language whereas JSON is a data format. Because of that although JSON is often viewed as a ‘replacement’ for XML – that is a flawed perception.

The reason JSON is viewed as a ‘replacement’ for XML is because it is good at transferring data. The JSON format is compact and its file size is smaller – making it transfer more quickly than XML.

At times you may even find it best to use tools that can export JSON data to Excel and then store it as XML. As long as you’re familiar with both, you can benefit from the advantages of each of them while using Excel to analyze the data.

On top of that JSON has a simpler structure and looks much cleaner than XML. The minimal syntax in JSON makes it easier for people to read and understand it – which is often why XML is criticized for being more ‘complex’ than JSON.

But the complexity of XML is not really a disadvantage – instead, it is simply due to the fact that it is a full-fledged markup language and not just a simple data format like JSON. Its ‘complexity’ allows it to use tag structures to describe data items, as well as support namespaces, comments, and ASCII, UTF-8 as well as UTF-16 encoding.

To add to all that, XML natively supports schemas – making it easier to structure and validate the data in a document. Technically JSON can use schemas, but only via the use of other extensions.

By far the biggest difference between XML and JSON is that JSON is easier to parse. All that is needed to parse JSON is a regular JavaScript function, while XML requires the use of an XML parser.

Even though some languages nowadays have built-in XML parsers – many do not. That makes parsing XML both difficult and slow, which is one of the reasons JSON is used to replace it in certain situations.

It is worth noting that although people often cite one of XML or JSON as being ‘more secure’ than the other, that isn’t necessarily the case. Both are prone to certain vulnerabilities depending on the settings or scripts that are used.

“Which is Better?”

As you can see the differences between XML and JSON go beyond a simple 1-to-1 comparison. And because of that, you can’t really consider one to be ‘better’ or ‘worse’ than the other.

Instead, what you can say is that JSON is better in some situations – while XML is better in others.

If all you’re interested in is simple data exchanges that do not require any concern regarding syntax or validation then JSON is generally the better option. It is clean, simple, widely-supported, – and more importantly fast, and easy to use.

On the other hand, if the data structure is important and you want to validate data and use syntax – then XML is definitely the way to go. It may be a bit more unwieldy, but it can do things that simply aren’t possible using JSON.

In most cases nowadays JSON is preferred for data delivery between servers and browsers because it is light and fast. However, for storing server-side information XML is still the more popular option due to its ability to organize data.

Keep in mind that the tools you use will influence your decision as well. Some may only support one of JSON or XML.


To be perfectly honest as things stand it is best to be fluent enough in both JSON and XML so that you can use either one as and when the situation calls for it. After all, it is highly likely that you’ll end up wanting to use JSON for data exchanges, and then XML for data storage.

It is safe to say that the popularity of both XML and JSON are unlikely to change – unless a third option comes along that manages to be as light and fast as JSON at data exchanges, while at the same time providing the organizational structure of XML when storing data.