How to determine whether the platform is safe and reliable?

Agree, though the demo will not tell you how to process the emotions but it gives the gist of the brokers’ trade execution speed and spreads in volatile sessions. I never trade directly in the live market when switching to another broker. Recently I have shifted myself to fxview after testing it on demo for a few weeks.

I like to read reviews from real people on multiple different sites and on Facebook as well. Seeing what real world traders think about a broker is so much more important to me than reading articles that may lean in one direction or another based on their affiliation with or against said broker. If you notice red flags, like a lot of complaints about withdrawal problems, then it's easy to know that you need to stay far away.

there are some tips how to determine a reliable platform.

firstly, start off with the broker, check all the regulations, licenses, certifications, maybe awards. don't regret the time on checking this information as it's fundamental thing for determining a proper broker. get acquianted with the customer support team, as a rule reliable brokers always concern about their customer support, because this team is liable for keeping traders' funds safe.
secondly, you should try it out. observe the broker's website, check the FAQ section, look through the platforms and conditions, then open a demo account. in fact, the only thing you have to do is just to try trading on demo.
so, if you were convinced n the reliability of the broker, try various indicators, lines on the platform and if there are no delays and the platforms works properly, then congrats you have found a good trading platform =)

I don’t think it is easy to find out about a trading platform before using it on your own. As most brokers offer you free demo accounts, you can simply practice trading with them. And when it’s time to go live, choose a service provider that has low trading costs and low minimum deposit requirements.

Been using Oanda for over seven years, they're fantastic!

3 things to check in a broker to determine its reliability - regulations, quick withdrawals, and customer support. And in my experience so far, I found aaafx, avatrade and xm fulfilling these criteria.