Luxembourg and Belgium are two of the countries people most often shortlist together when moving to the EU. Below is an honest side-by-side on the things that shape daily life, with the stronger country marked on each row. On these measures Luxembourg comes out ahead on 7, Belgium on 2.
Rent is the clearest split: a one-bed runs about EUR 1,900 a month in Luxembourg against EUR 950 in Belgium, so Belgium saves you roughly EUR 950 every month.
Typical net pay is EUR 3,500 a month in Luxembourg and EUR 2,300 in Belgium, putting Luxembourg EUR 1,200 ahead before anything else is counted.
What actually matters is the money left after rent: EUR 1,600 in Luxembourg against EUR 1,350 in Belgium, which is where Luxembourg pulls ahead.
You will get further on English alone in Luxembourg than in Belgium, which matters most in the first year, before the local language clicks.