Monero Seed Phrases: 25-Word vs Polyseed vs 12-Word Explained

Your seed phrase is the only thing that truly matters in a Monero wallet. Apps come and go, as MyMonero and Exodus users learned in the last two years, but a correctly stored seed can always bring your funds back. The confusing part is that Monero now has several seed formats, and not every wallet reads every one. This guide explains each format, which wallets understand it, and how to back it up properly.

What a seed phrase does

A Monero wallet is defined by its private spend key. The private view key and your public address are mathematically derived from it. A seed phrase is a human-friendly encoding of that secret: a list of words you can write down and type back in later.

From the seed, any compatible wallet can recreate:

• your private spend key (full control),
• your private view key (read-only visibility),
• your primary address and all subaddresses.

The getmonero.org FAQ makes the same point in plain words: coins are recorded on the blockchain, and the seed you saved lets you restore your wallet at any time.

Key point: Whoever has your seed has your money. No support team, developer or exchange can reverse a theft or recover a lost seed.

The three formats you will meet

There is also an older 14-word format used by early Feather versions before 2.0.0. Feather can still restore it, but it is deprecated.

25-word legacy seed

The classic Monero format. Twenty-four words encode the key, and the 25th is a checksum. It is supported by essentially every Monero wallet, which makes it the most portable backup. Its weakness is that it says nothing about when the wallet was created, so you should write down a restore height or creation date next to it. Without one, a restore can scan from a very early block and take a long time.

16-word Polyseed

Polyseed is a newer design that packs more into fewer words. According to the Monero documentation, its 16 words carry the secret, a checksum, a few feature bits and the wallet’s approximate creation date. The date range it can represent starts in November 2021, and the wallet converts it into a restore height automatically.

Other useful properties:

• It uses BIP39 wordlists, so the words are familiar and the first four letters of each word are unique.
• It supports a seed offset (passphrase) that changes the derived keys without changing the written words.
• Feather notes that a 25-word or 14-word seed cannot be converted into a Polyseed. If you want a Polyseed, create a new wallet and send your funds to it.

Feather can display a 25-word version of a Polyseed wallet (Wallet, Seed, “Show 25 word seed”). That is handy as a compatibility backup for wallets that only accept the legacy format.

12-word BIP39 seed

Multi-coin apps sometimes derive Monero keys from a standard BIP39 phrase so that one backup covers several coins. Cake Wallet offers this as an option, and Exodus used a 12-word phrase. The catch is that the way Monero keys are derived from BIP39 is not universal. A 12-word phrase may restore correctly only in the app that created it, or in apps that document support for that specific method. When Exodus ended Monero support in August 2025, it pointed users to Cake Wallet, which can restore both its 12-word phrase and its 25-word Monero mnemonic.

Tip: If you use a BIP39 seed for Monero, also export or note the 25-word Monero seed if your wallet can show it. That gives you a fallback that nearly any Monero wallet can read.

Which seed should you choose?

• New desktop user: Polyseed in Feather. Short, dated and easy to restore.
• New mobile user: Polyseed in Cake Wallet, or legacy 25-word if you want maximum portability.
• Multi-coin convenience: BIP39 in Cake Wallet is fine, as long as you understand the portability trade-off.
• Long-term savings: a hardware wallet, whose recovery phrase is managed by the device, or a 25-word or Polyseed wallet created on an offline machine.

How to back up a Monero seed properly

1. Write it by hand on paper, or stamp or engrave it on metal for fire and water resistance.
2. Number the words and double-check the spelling. With Polyseed and BIP39 lists, the first four letters are enough to identify each word.
3. Add the wallet type and date, for example “Feather Polyseed, created Oct 2026” or “Monero GUI 25-word, restore height ####”.
4. Store it in at least two separate safe places. One copy at home and one with a trusted person or in a safe deposit box is common.
5. Never photograph it, email it, or paste it into a cloud note. Screenshots end up in cloud backups.
6. Test it. Restore the seed on a spare device or a fresh wallet file and confirm the address matches. Then delete the test copy.

Warning: Scammers post fake “wallet validation” or “seed recovery” sites and impersonate support staff in Reddit and Telegram DMs. Any site or person that asks for your seed is trying to steal your XMR.

Passphrases (seed offsets)

A passphrase adds a second secret. The seed plus passphrase “A” gives one wallet; the same seed plus passphrase “B” gives another; the seed with no passphrase gives a third. This protects you if someone finds your written seed. The risk is forgetting the passphrase, which locks you out permanently. If you use one, store it separately from the seed and include it in your restore test.

The Monero Polyseed specification also defines an optional encryption feature, but the documentation says most wallets, including the core Monero wallets, do not implement it and it is not generally recommended. Use the standard seed offset instead.

Keys you might be asked for, and what they reveal

A view-only wallet uses your address plus private view key. It is a safe way to monitor a cold wallet’s incoming funds from a phone or server. Because spent outputs need key images to be detected, a view-only wallet may not show outgoing spends correctly unless you import key images from the full wallet.

Common seed mistakes and how to avoid them

Support forums see the same backup mistakes again and again. Most are easy to prevent:

• Writing the seed but not the format. Months later you find 16 words and cannot remember which app made them. Always label the backup with the wallet name and seed type.
• Skipping the 25th word. The legacy format’s last word is a checksum. Some people assume it is optional and stop at 24. Wallets will reject the seed or, worse, you will doubt a correct backup.
• Mixing up the wallet password and the seed. The password you type to open the app only encrypts the local wallet file. It cannot restore anything on a new device. The seed can.
• Relying on the app’s cloud backup alone. Some mobile wallets offer encrypted cloud backups. They are convenient, but if you forget the backup password or lose the cloud account, only the written seed saves you.
• Keeping one copy. A single sheet in a drawer is exposed to fire, water and house moves. Two copies in two places is the minimum.
• Never testing. An untested backup is a guess. A five-minute restore test turns it into a fact.

What to do if you think your seed was exposed

If your seed may have been seen, photographed or typed into a suspicious site, assume it is compromised. Create a brand-new wallet with a new seed, back it up properly, and send all funds from the old wallet to the new one as soon as possible. Changing the app password does nothing, because anyone with the seed can rebuild your wallet elsewhere.

Migrating from a discontinued wallet

If you still have a seed from a wallet that no longer supports Monero:

• MyMonero (offline since 6 January 2026): restore the 25-word seed in Cake Wallet, Feather or Monero GUI with a restore height or date before your first deposit.
• Exodus (Monero support ended 18 August 2025): restore the 12-word Exodus phrase in Cake Wallet, or the 25-word Monero mnemonic in any Monero wallet. Exodus suggests 26 April 2019 as a restore date if you are unsure.

Once your funds appear, consider sending them to a fresh Polyseed wallet so your backup is modern, short and dated.

For restore heights, sync problems and hardware wallets, see the rest of our Wallets category.