Dorm vs private
A shared dorm (typically 4–10 beds) is still the cheapest bed in the country at £20–35 a night, but a growing share of hostels now sell their own private, en-suite rooms at a price close to a budget chain hotel — useful if you want the communal spaces without sharing a room.
The names you'll actually see
YHA (the Youth Hostel Association, a long-running nonprofit with properties scattered through national parks as well as cities) sits alongside independent city chains like St Christopher's Inns, Clink, Safestay and generator — each with its own house style, from quiet and basic to a hostel built around its own bar.
What's included
A communal kitchen and lounge are close to universal, and many throw in free walking tours, pub crawls or a basic breakfast. Lockers are standard in dorms, though some hostels expect you to bring or rent your own padlock — worth checking before you arrive.
Who it suits
Solo travellers and anyone prioritising budget and meeting other people over privacy get the most out of a hostel stay; families and very light sleepers booking a shared dorm are usually better served by a private room, hostel or otherwise.
How to find a good one
Hostelworld's own breakdown by category — atmosphere, cleanliness, security, location, staff — is more useful than the single overall score, since a hostel built around its bar and one built for quiet solo travellers can both score well overall while suiting very different trips. YHA membership (or HI membership if you already hold one from home) knocks a few pounds off every stay at YHA properties and tends to pay for itself after two or three nights.
What to check before you book
Some hostels, especially the livelier independent ones, run a daytime lockout or an overnight curfew — worth checking if you're arriving on a late train. A number default to single-sex or family-only dorms rather than mixed, and locker sizes vary enough between hostels that a full-size backpack doesn't always fit the smaller ones, so bringing your own padlock and checking locker dimensions in reviews is worth the two minutes.