What's the secret to cheap lodging actually in Copenhagen?

I suspect the answer to that question depends on the precise dates you're looking at. Not only will the month matter, but the days of the week could also be a factor. I'm sure Copenhagen is popular for weekend getaways.

I just took a quick look at booking.com for a random period (3 nights beginning on Tuesday, May 12) and there were lots of places under €120 / night (not all of them hotels with dorm rooms, sleeping pods, etc.), but that figure excludes the 25% V.A.T., so this is looking like a serious challenge.

You might check out the Wakeup chain and see whether it would be acceptable to you and there's a location that seems practical.

There's also the Cabinn chain, but its outposts seem to have significanly lower ratings. I didn't read the reviews, so I don't know what the issues might be.

As much as I like Malmö, don’t forget that round trip on the train can cost €30 or more, plus the cost of the metro portion. And it can take 45 minutes to get from Malmö to the center of Copenhagen.

Another inexpensive option is a private room in a shared Airbnb.

What's the secret to cheap lodging actually in Copenhagen?

Redefining 'cheap' to be a higher number?

Yeah, Copenhagen is not a cheap city. 120€ is 900 DKK (Denmark does not use the euro), and while not impossible it is a tight budget for sure. The best “secret” is to avoid the high summer and be flexible with the dates and the location. When I suggest flexibility with location, I don’t mean Malmö. I concur with Barb’s point. When Copenhagen is your destination, the time and cost of transportation makes Malmö a bad choice. Otherwise there’s nothing wrong with Malmö, but it’s not Copenhagen.

I have stayed with the Cabinn chain a couple of times. They’re nothing to write home about, and the rooms are basic and small - but they’ve been clean and it works. I hear that Wakeup is also fair budget choice, but I’ve never stayed with them. The Scandic chain is midrange, but you can also find a good deal every now and then - they typically cost a bit more, but they’re also more “proper” hotels. There’s also a Danhostel in Copenhagen. I haven’t stayed at this specific Danhostel, but a lot of them have private rooms you can book, which can be a good budget option (but check if it has its own bathroom, as that’s not always guaranteed).

We were able to take advantage of the Choice hotels points program. Very reasonable award rates. If you don't participate you can join and purchase points for which there are often very good promotions. Then run the numbers to see if it works out for the budget. For us it made a very expensive area affordable especially if you get in one of their Home hotels where in addition to breakfast, you get tea and a quite adequate evening meal included.

I have long wanted to visit Tivoli Gardens at the height of summer but it might have to wait for the off-season, unless I suddenly show up in some heretofore unknown rich relative's will.

The current Choice Privileges points sale ends tomorrow. Wyndham Rewards the day after. As mentioned above by greg1262002, buying points can be a great money saver, at least in hotel programs that still have fixed redemption rates with good options in places like Copenhagen. For Malmo or beyond, also check out the Strawberry Hotels 2026 Summer Pass promotion (budget or standard versions).