In Copenhagen you lose the home if you write half-heartedly and late. Private landlords typically ask for ID, payslips or student grant, references and a clear date. If you have that ready, you are in play. If you do not, the let goes to the next person. That is especially true for 1- and 2-room homes in the bridge districts and the new harbour areas, where there are more tenants than keys.
Social housing is another track: registration, waiting time, often requirements for household and estate. It cannot be rushed because you have given notice on your old let. If you run both tracks, keep two timelines. Sublets and cooperative flats for temporary rent are a third track with a shorter horizon and other rules. Read whether you may have pets, whether you may sublet a room, and what happens when the period ends.
Two homes with the same rent can have three months of deposit versus five, on-account charges that cover heating versus electric heating, and a pet ban versus permission. Those are the figures that decide whether you can move in at all. Use the filters on the list for what is non-negotiable, and let the market figures below show where the current supply sits — not where you wish Copenhagen sat.