Type Oxford dictionary into a search bar and you expect one website. There are several, and the line between free and paid runs right down the middle of them.
The honest answer depends on which Oxford you mean. The famous one costs money. The one you probably read already today is free, and you never clocked that it was Oxford.
The famous one is not free
When people picture the Oxford dictionary, they usually mean the Oxford English Dictionary, or OED for short, the huge historical one that fills twenty printed volumes. It sits behind a paywall. A personal subscription is about $100 a year, or ten dollars a month if you would rather pay monthly. There is no free tier and no ad-supported version.
That fits what the OED actually is. It was never built as a quick-definition site. It is a thousand-year record of the language, tracking every word, every sense, and the first time each one turns up in writing, and it takes a paid staff of lexicographers to keep going. The subscription pays them.
Your library card probably opens it
Before you reach for a card with a number on it, check the one already in your wallet. Most public libraries pay for an OED subscription and give it to every member for free.
On the OED site you click Sign in with library card, pick your library, and type your card number. That is the whole cost. A library card you have had for years turns the hundred-dollar dictionary into a free one you can read from home tonight.
The free Oxford you already use
You read Oxford for free most days without paying anything. Google a word and the tidy definition at the top of the results is Oxford's work.
Every time you Google a word, that definition box is Oxford. It just never carries a logo.
The dictionary app built into a Mac is Oxford too, along with a handful of others. Oxford licenses that data out under the name Oxford Languages, and it has been sitting inside those search boxes for years. It is not the full OED entry with the quotations and the history. It is the short, everyday meaning. But it is genuinely Oxford, it is free, and it is already one search away.
Oxford Learner's Dictionaries, free on purpose
There is also a free Oxford site you can go to directly. Oxford Learner's Dictionaries is open to anyone, with no login and no subscription, and it is built for people learning English. You get plain definitions, audio in British and American voices, and example sentences written so a learner can follow them.
What you do not get is the full historical record. It trades the OED's depth for clear, usable English, which for most everyday questions is the version you actually want.
The free one that closed
If you remember a free Oxford dictionary that just worked, and then one day did not, you are not imagining it. Lexico was Oxford's free general dictionary, run together with Dictionary.com, and it closed on 26 August 2022. Go to the old address now and it sends you to Dictionary.com, which is not Oxford at all.
So the ground has shifted. The free general Oxford site is gone, the paid OED needs a subscription or a library login, and the everyday definitions have moved into other companies' search results. There has not been a single clean answer for a few years now.
Where Linguin fits
Linguin works the other way around. It is free to look up, with no card and no login, and it is a live multilingual dictionary rather than a static English one. The OED explains English in English. Linguin covers more than 120 languages and gives you the meaning in the one you actually think in.
The live part is what a printed dictionary can never do. Slang, idioms, and internet memes get full entries while they are still spreading, so you can look up aura farming now instead of waiting years for an editor to sign off on it.
It also reaches past the languages people grow up speaking. Klingon, Dothraki, and Esperanto have real entries too, so you can look up Qapla', khaleesi, or saluton and get the same kind of definition as any word from a spoken language.
Free, if you know where to look
So, is the Oxford dictionary free online? The famous OED is not, at least not on its own site, though your library card most likely opens it. The everyday Oxford definitions are, tucked inside Google and your devices. The free Oxford website people miss has been gone since 2022.
Free is out there. It is just split across a paywall, a library login, and a site that no longer exists. When you would rather not hunt for the free door, look the word up on Linguin, save the ones you want to keep, and drill them in exercises.