Why does it take Monero so long to sync?

Monero (XMR) is organized differently from Bitcoin and many other blockchains. Its architecture is designed for strong privacy, which makes syncing both the wallet and the node more complex and slower. Since many Monero users struggle with using the coin, let's dive deeper into Monero's architecture.

Privacy at the Cost of Speed

Monero implements three key privacy technologies:

1. Ring Signatures: A ring signature is a type of digital signature that can be generated by any member of a group of users, each of whom has their own key. No one can determine which group member actually created the signature.

2. RingCT (Ring Confidential Transactions): RingCT is an enhanced form of ring signatures. It uses a method known as a "Multi-layered Linkable Spontaneous Anonymous Group signature," which hides the amount, origin, and destination of a transaction. It also supports efficient, verifiable, and trustless coin creation.

3. Stealth Addresses: These require the sender to generate a unique one-time address for each transaction on behalf of the recipient. The recipient can share a single public address, but each incoming payment will go to a different address on the blockchain. These addresses can’t be linked back to the recipient’s main address or to each other. Stealth addresses ensure that only the sender and the recipient know where the payment was sent.

Each of these privacy features increases the size and complexity of the data the wallet must process during synchronization. As a result, the initial loading and scanning of the Monero blockchain can take significantly longer than with blockchains that don't include these privacy protections.

How Do Monero Security Technologies Work in Practice?

Thanks to these three privacy methods, all transactions on the network are private by default — there's no way to accidentally send a transparent transaction. This feature is exclusive to Monero.

In practice, these features work together — but they also slow things down. Let's look at the process.

Let's say you want to send Monero to a friend.

Step 1: Getting Your Monero Keys

When you set up a Monero wallet, you receive a private view key, a private spend key, and a public address. The spend key lets you send payments, while the view key allows you to see incoming transactions sent to your wallet. The public address is what you share to receive funds.

Step 2: Creating Your Transaction

To create a transaction, your wallet first scans for outputs associated with your account — in other words, unspent XMR you've previously received. These outputs are then used as inputs for the new transaction.

In Monero, the set of unspent outputs (UTXOs) effectively includes all transaction outputs. Because of ring signatures, it's impossible to definitively mark a specific output as spent — any given output can appear multiple times in other users' transaction rings as a decoy.

As a result, full Monero nodes must store information about every output since the genesis block and can't discard spent outputs like Bitcoin nodes do when pruning old UTXOs. This increases both storage requirements and the complexity of indexing.

As a result, the Monero blockchain is significantly larger than Bitcoin’s when comparing a similar number of transactions. For example, as of 2025, the full Monero blockchain exceeds 220 GB — even in pruned mode, it's still around 95 GB and growing.

Next, you need to hide which specific XMR you're spending. The wallet picks several random outputs from the blockchain — along with the one you're actually spending. This forms a group (called a ring) that makes it impossible to know which output is the real one.

Step 3: Creating the Recipient’s Stealth Address

Monero never sends XMR directly to the recipient’s public address. Instead, the wallet uses the recipient’s public address to generate a unique one-time stealth address for that transaction. This means the address recorded on the blockchain can’t be linked back to the recipient.

As a result, only the wallet owner (who holds the private view key) can tell which outputs belong to them. During synchronization, the wallet scans every block and transaction, trying to decrypt each output using the private view key. In other words, it “scans” all outputs to check whether they were meant for the user.

This process involves heavy computation and constant disk I/O. Even if your address shows up in just 0.1% of transactions, the wallet still has to check them all — that’s the tradeoff for hidden addresses and always-on privacy.

For example, if you haven’t opened your wallet in a month, the next time you launch it, it will have to scan all blocks from that period — potentially tens of thousands of transactions — to look for incoming funds. Unsurprisingly, this takes noticeable time on an average device.

Step 4: Encrypting the Amount

The next step is encrypting the amount being sent. This is important: unlike most other cryptocurrencies, no one can see how much you're sending in a Monero transaction — not the miner, not an outside observer, not even the recipient until they decrypt it with their keys.

This is made possible by RingCT (Ring Confidential Transactions), a system Monero uses to hide transaction amounts. Each RingCT signature increases the transaction size and must be verified during synchronization.

Since 2017, all Monero transactions have used RingCT, which hides the amount being sent by adding cryptographic range proofs. Bulletproofs have significantly reduced the size of these proofs, but nodes still have to verify the range proof for each output when processing blocks.

Ring signatures and RingCT together offer strong privacy — but they also make full block verification much harder in Monero than in Bitcoin. Nodes must not only validate spending signatures, but also check that the hidden amounts are correct.

Step 5: Signing and Sending the Transaction

Once everything is ready — the inputs are masked, the recipient’s address is hidden, and the amount is encrypted — your wallet signs the transaction using your private key. This proves you’re authorized to spend those coins.

Then it sends the transaction to the network, where it’s added to the blockchain. Miners include your transaction in a new block. Once that block becomes part of the chain, the transaction is confirmed.

Now it’s permanently recorded on the blockchain — but all you see is a cryptic string, with no way to tell who sent what, to whom, or how much.

How Monero Nodes and Wallets Work

To store the blockchain, process and verify transactions, and help wallets communicate with the network, Monero uses a node program called monerod.

A Monero wallet connects to a node to interact with the blockchain. The node provides blocks and network data, and the wallet uses this data to scan locally for transactions relevant to the user — using their private keys.

When sending XMR, the wallet creates an encrypted, anonymous transaction, signs it, and passes it to the node. The node verifies it and forwards it to the network. This way, the wallet doesn’t store the blockchain itself. It relies on the node as an intermediary — but the node can’t tell who’s processing what.

The initial synchronization of a full Monero node also depends on network speed and hardware performance. Monero’s blockchain has no fixed block size limit — it’s dynamic and can grow under load.

Because Monero is less widespread than Bitcoin, there are fewer nodes. Combined with bandwidth or peer limitations, this can slow down blockchain syncing.

However, Monero nodes support pruning mode, where only about one-third of the blockchain data is stored. This keeps one-eighth of each ring signature for compatibility, without losing transaction history.

A pruned node (around 95 GB) still fully validates transactions and helps maintain the network, so many users choose it to save space and speed up syncing.

Monero's Long Sync Time: A Tradeoff for Privacy and Architecture

Both the node and the wallet have to load a large amount of data — hundreds of thousands of blocks and hundreds of millions of outputs — and run complex cryptographic checks on each one. The wallet doesn’t instantly know which transactions belong to you — it has to look under every cryptographic layer, scanning all blockchain data to find them.

Even with optimizations like parallel scanning and caching, launching a Monero wallet for the first time is always a test of patience.

The developers put it clearly:

“Be patient, and if you would like to sacrifice some privacy for faster sync times, consider using a remote node or lightweight wallet instead.”

However, this brings us to another important question: how do you choose the right Monero wallet?
We’ll cover that in our next article.