Is it really worth the time, money and effort? While there is no definite answer that applies to everyone, here are some things to consider.

What is the purpose of the JLPT?

The JLPT tests how well you know and understand Japanese. It is the standard test that is accepted and recognized worldwide.

In what cases are the JLPT certificate needed?

A JLPT certificate that proves your Japanese ability is needed primarily for work and study. If you plan on getting a job in Japan that requires you to use Japanese, a JLPT certificate will most likely be required.
There’s some cases that a company employee could not get promoted until they submitted a JLPT N1 certificate. The certificate was requested even though they have been working at the company for several years.

Not all jobs require you to have JLPT N1 some companies require only a minimum of JLPT N2.

In order to be accepted into a Japanese language program here in Japan, you need to submit a JLPT certificate. Even passing the JLPT N5 is enough since the certificate is needed so students can be placed in a class that is appropriate for their level. To be admitted to a bachelors or other program at a Japanese University, a JLPT certificate may or may not be mandatory. Many universities consider the Examination for Japanese University Admission (EJU) when making admission decisions, however if you can pass the JLPT it may give you an advantage when taking the EJU.

Private scholarships such as the Panasonic scholarship may also require a JLPT certificate.

What are the benefits of taking the JLPT?

Taking the JLPT forces you to study, and study not just what you like but what you need to know. That is the biggest benefit. The exam has a fixed date and a more or less decided curriculum. Studying for the JLPT means you study the entire curriculum.

On other, many people will simply skip the parts of the language they don’t like, grammar comes to mind, or just overlook other parts, listening comes to mind.  The JLPT requires exam takers to be comfortably proficient in everything except speaking in order to pass the JLPT.

Why take the JLPT if you don’t need it?

If you do not need a certificate for work or school then only you can decide whether to take the JLPT or not.  Many students who take the JLPT do so because it makes them study and helps confirm or gauge their progress in the Japanese language.

For others, it gives them a goal to work towards and makes them they learn faster instead of dragging their feet.  The exam date serves as a motivation to learn things now instead of later.

For people who are studying Japanese on their own, staying motivated is sometimes difficult.  Taking the JLPT and paying the exam fee is a huge incentive to study consistently and at a reasonable pace.

Taking the JLPT is worth it if you plan to study, or work in Japan; otherwise not taking the exam has no consequences. Choosing to take the exam can provide a curriculum for self-study, motivate you to study consistently and may allow you to learn the language more quickly.

Source: JLPTWALLCHART