6 hour layover in Amsterdam on the way to Rome

I don’t think you have enough time. If all went well upon landing and going through immigration, say one hour, then a taxi, you might have 2 hours before having to head back to go through safety screening, etc.

My initial response is no. I'd stay on the airside, go through passport control, locate my departure gate for Rome, find a place to ease out and have breakfast.

There are too many variables to consider, especially when you are arriving jet-lagged to a place you know nothing about.

Keep in mind that you will have to go through passport control and find your way to your departure gate in time to be there at the time your airline wants. The plane could be late. Passport control could take longer than you might imagine, especially if several planes arrive at about the same time. So could locating your departure gate.

And you don’t say when you are going. If it's soon, according to the links I've posted below, Covid protocols could slow things down considerably. See especially the link and info on transferring below.

Full disclosure: Schiphol is my favorite European airport. It's where I arrive and depart from whenever I can. But I've never had a layover there. I've used Amsterdam as my starting and ending place for those trips.

This is a link to the Schiphol website in English.

This is a link to the section on transfers. This is from that section:

Do I need to take another test when transferring? No, that is not necessary. If you stay at Schiphol during your transfer, you do not need a new negative COVID-19 test result. The test result you had upon arrival at Schiphol remains valid during your transfer, including any potential delays. If you leave Schiphol during your transfer, this counts as a new journey and you are required to present a new negative test result. You can find out more on the Dutch government website.

This is a link to an interactive map of the airport as well as to pdfs of different parts of it. Places to eat are shown. They are identified as before and after security on the interactive map. If you stay airside, you will be after security and you can even find places near your gate.

My answer is ‘it depends’. Have you been in Europe before, how comfortable are you with getting to town, and what is your risk tolerance.

I just did something similar to what you are proposing earlier this week but with some caveats.
- I was traveling between Tallinn, Estonia and Prishtina, Kosovo with stops in Warsaw and Vienna (no jet lag issues since we had already been in Europe for 10 days)
- My layover in Warsaw was 6.5 hours
- I had been to Warsaw a couple of times previously
- I just took a Bolt (similar to Uber) back and forth and spent a comfortable 3 hours wandering in Warsaw
- Once we got tired headed back to the airport and still had an hour and a half before departure
- Keep in mind that Warsaw is much smaller than AMS

I wouldn't chance it. You could take the train into Amsterdam, which is about 20 minutes. But what would you do after that? Believe me, breakfast in Amsterdam is nothing to go out of our way for. You could take a tram ride. The # 12 gives you a nice tour of the city.
I would be concerned about getting back through Security. It's a two part process here. Once at Security and once at the gate. I would wonder if they might not be curious as to why you left.

I’m wondering why there would be additional security at the gate for a schengen flight. Also, no one will ask why you are going through security

Truly Arnold, I do not know. That does make sense. I have only taken flights from AMS to the US, so I am basing on that procedure.

I posted my experiences Flying Intra-Schengen from AMS earlier this week. Frankly, if you HAVE your boarding pass to Rome, and any checked luggage is already being sent to Rome (if your flights are all on the same ticket), then upon your return to the AMS airport from Amsterdam. you would scan your boarding pass to enter the AIRSIDE area, then go through security (X-ray), and from there, you would simply walk to your assigned departure gate. Our last few times departing from AMS we presented NO COVID info, no QR code, no CDC card, not even our passports... and had no temp check... really nothing different than flying intra-Schengen two years ago.

That said, I'd play it by ear. I'd not pay in advance for anything - like a tour or Anne frank tickets - as your arriving plane may be delayed or arrive late. But if you're flexible, it could work. We usually fly back and forth from AMS 3-4 times a year to the USA (well - not last year!!) and often, with the tailwind our inbound flights often arrive early at AMS.

I'd buy my train tickets to and also back from Amsterdam Centraal... saves you time on the return and they don't cost much if you have to bail and grab a taxi. You're departing from Track 1-2 at AMS. Amsterdam will probably just be waking up, but that's a great time to see the city. Go to the NS website and KNOW WHEN your return-to-AMS trains are departing (The NS Site will also give you the Track #) and give yourself a 2-train time slot cushion and you should be good. Definitely set yourself a "NO MATTER WHAT, WE'RE RETURNING BY" xxxxx time.