How long does it currently take to renew a Belgian passport?

Filing your application online before you go to the municipality saves you like two weeks. For a standard renewal, expect 4 to 6 weeks depending on the region right now, but some municipalities move faster, others are a real pain. Call your municipality directly before you go, they'll give you the actual timeframe there, it makes all the difference.

I renewed mine a few months ago and waited a bit over 5 weeks, but I hadn't done the online process beforehand - that was a big mistake on my part. If you do it properly from the start, you save time, like a week or two depending on what they told me at the town hall. But it really depends where you live, because small municipalities sometimes move faster than big overloaded cities.