The JLPT is the same exam everywhere - the same paper, the same scoring, the same certificate. Where you sit it changes only the practicalities, but those are worth planning around.
How many times a year
In Japan: twice, in July and December, at all levels.
Overseas: twice a year in many countries, but a number of cities hold only the December sitting, and not every level is offered at every site.
That last detail catches people. Check which levels your nearest city offers before building a plan around a July attempt.
Seats and deadlines
Registration in Japan is straightforward but popular sites fill. Overseas, both the application window and the number of seats are often tighter, and in some countries places sell out within days of opening.
The practical rule is the same everywhere: diarise the opening date, not the closing date. How to register.
Identification
In Japan, a residence card is the usual document. Overseas it is typically a passport or national ID.
Whichever it is, the name must match your application exactly, and you must bring the original - see the photo and ID checklist.
Results
Results are published online, with certificates following by post. Timing differs between Japan and overseas sittings, with overseas results generally arriving a little later.
If a deadline depends on the certificate - a job offer, a university application, an immigration filing - build in more margin than the published schedule suggests. Results and certificates.
Does it matter to an employer?
No. The certificate does not say where you sat it and nobody asks. An N2 obtained in Kathmandu is an N2 obtained in Osaka.
What does matter is the date, since some employers and institutions prefer a result from the last couple of years. The certificate itself does not expire: results and certificates.
Which to choose
If you are already in Japan, sit it in Japan - more sittings, more centres, less travel.
If you are abroad and planning to move, sit it at home rather than waiting to arrive. Arriving in Japan with the certificate already in hand changes what jobs you can apply for on day one, and the exam is not cheaper or easier in Japan.
And if the reason for the certificate is a Specified Skilled Worker visa, consider the alternative: JFT-Basic runs roughly monthly at Prometric centres across the main source countries, so a missed attempt costs weeks rather than months. JFT-Basic or JLPT, and the free exam demo will place you on its scale today.