What Monero hides, and how
Three mechanisms, each removing something an explorer would normally show.
Stealth addresses mean the recipient's address never appears on chain. Each payment goes to a unique one-time address derived from the recipient's keys, so nobody watching can tell that two payments went to the same person.
Ring signatures mean the sender is one of a set of possible senders, and which one is not determinable. Every transaction input references several plausible past outputs, only one of which is genuinely being spent.
RingCT hides amounts. The network verifies that inputs equal outputs without learning what either is, using cryptographic commitments.
The combined effect is that a Monero explorer can tell you a transaction exists, when it was confirmed, how large it is in bytes, how many inputs and outputs it has, and what fee was paid. It cannot tell you who sent it, who received it, or how much moved.
Proving a payment without revealing it
This is the part that matters practically. If someone claims to have paid you, you cannot verify it by opening a link — there is nothing to see.
Monero solves this with view keys and transaction proofs. The prove payment tool takes a transaction ID, the recipient address and a transaction key supplied by the sender, and confirms whether that payment was made and for how much. The check output tool takes your private view key and shows which outputs in a transaction belong to you.
The crucial detail is that Onion Explorer performs these checks locally in your browser rather than transmitting your keys to the server. That distinction is the difference between a useful tool and a catastrophic one, and it is a good reason to prefer an instance whose code you can read.
Never do this
Never paste a private view key, and absolutely never a spend key, into a site you have not verified. A view key reveals your entire incoming transaction history to whoever holds it. Any page asking for a spend key is stealing from you — that key moves funds. If you are not certain the check happens locally, run the explorer yourself or use your own wallet, which does the same verification.
This is also why fake explorers are a particular danger on Monero. A cloned Monero explorer that harvests view keys collects something far more valuable than a Bitcoin explorer clone ever could.
Why privacy has to be mandatory to work
Ring size is the field on a Monero transaction page worth understanding, because it is the privacy parameter. Monero enforces a minimum at the protocol level, which means every transaction has that many plausible senders.
The design lesson here is more broadly applicable than Monero. Optional privacy tends to fail, because the small group using it stands out — a transaction that opts into anonymity is itself a signal. Monero made it mandatory, so the anonymity set is the entire chain and there is no low-privacy majority to contrast against.
You can see the alternative approach on Litecoin's MWEB, where confidentiality is optional and a peg-in is therefore publicly visible as an act. Both designs are defensible; only one of them makes the choice itself unobservable.
For anyone thinking about their own on-chain footprint, that distinction is the useful takeaway, and it applies to far more than cryptocurrency.
Why you should probably run your own
The argument is stronger here than on any other chain we cover. Monero exists because its users care about privacy. Querying a public server about your own transactions partially undermines that — even if the server learns nothing about amounts, it learns which transaction IDs you asked about and from where.
Onion Explorer is open source and runs against your own monerod node. The chain is far smaller than Bitcoin's, so the storage requirement is modest by comparison, and a Monero node is a realistic thing for an individual to run.
If self-hosting is not practical, use an instance over Tor and rely on your own wallet for anything involving your keys. A wallet can verify an incoming payment without any explorer at all, which is the strongest option available and the one people most often forget exists.
Our self-hosting guide covers the practicalities across chains. Monero is the case where the effort-to-benefit ratio is most favourable by a clear margin.
Three misconceptions worth clearing up
Monero attracts more confident misinformation than any other chain we cover, in both directions. Three points are worth stating carefully.
It is not untraceable in an absolute sense. The privacy guarantees are strong and they are probabilistic rather than perfect. Ring signatures give plausible deniability across a set, not certainty. Research into statistical analysis of Monero is active and ongoing, and the protocol has changed repeatedly in response to it. Anyone telling you it is mathematically impossible to analyse is overstating the case.
It is not fully opaque either. Transaction timing, size, fee and the fact that a transaction occurred are all public. Network-level observation — which node broadcast first — is outside the protocol's protection entirely, which is why running your own node and using Tor matter.
Privacy is not the same as anonymity from everyone. If you buy Monero on an exchange that holds your identity documents, that exchange knows you hold Monero and how much you withdrew. The chain hides what happened next; it does not unhappen the part that was recorded elsewhere.
We make these points because an explorer is where people go to test claims, and on Monero the explorer cannot test most of them. That limitation is worth understanding before you rely on any of it — in either direction.