Security assessment · reviewed 2026-08-10

Is Sparrow Wallet safe? An honest security review

Short version: the software is non-custodial, open source under the Apache 2.0 licence, and free. None of that makes your bitcoin safe on its own. "Safe" is decided by the configuration you choose and the state of your backups, and Sparrow will let you build something excellent or something reckless with equal willingness.

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Non-custodial
Apache 2.0 source
Free, donation funded
Argon2 encrypted wallet files
No published third-party audit

Unofficial

The direct answer, before the detail

Sparrow holds no coins. It is a desktop program that watches addresses derived from keys you control and builds transactions that spend them. There is no account, no balance sitting on someone else's server, and no password reset, because there is nothing on a server to reset. That structure removes an entire class of risk: the company cannot freeze you, lose your funds in a bankruptcy, or get breached with your coins inside.

In exchange it hands you every risk that a custodian would normally absorb. If your computer is infected, if you install a tampered copy, or if your recovery words end up in a photo library, no part of Sparrow's design saves you. The wallet is honest about this and so is this page: the question is never "is the app safe", it is "is my setup safe", and those have different answers.

So read the rest of this page by attacker. Security is not a score out of ten; it is a list of specific people trying specific things, and of which ones your configuration actually stops.

Threat model

Six attackers, and what Sparrow does about each

Feature lists are a bad way to judge security. Attackers are a good way. Each card below is someone with a plausible path to your coins, what Sparrow genuinely blocks, and what it cannot.

1. Malware already on your computer

Infostealers sweep for wallet files, log keystrokes and swap bitcoin addresses in your clipboard as you paste them.

Sparrow helps: Wallet files are encrypted at rest, and the transaction editor shows the exact output addresses and amounts before you sign, so a swapped address is visible if you read it.
Sparrow cannot: Protect a key that is decrypted in memory on a machine the attacker controls. A hardware signer solves this properly; the device shows the address on its own screen.

2. A tampered or fake download

Search ads and lookalike domains serve modified installers. This is the most common way a first stack disappears, and it costs the attacker almost nothing to set up.

Sparrow helps: Releases ship with a signed manifest of file hashes. Verify the signature against fingerprint D4D0D3202FC06849A257B38DE94618334C674B40 and a swapped binary fails the check.
Sparrow cannot: Stop you skipping verification. Nothing in the installer warns you that you got it from the wrong domain. Verify a download properly.

3. The Electrum server operator

Lightweight wallets ask a server which transactions touch their addresses. Whoever runs that server learns your whole address set and your IP.

Sparrow helps: Built-in Tor hides your IP, and you can point it at your own Bitcoin Core node or a private Electrum server instead of a public one.
Sparrow cannot: Make a public server forget what you already told it. This is a privacy failure, not a theft one — the operator cannot spend. How address leakage works.

4. Physical theft of the file or laptop

A stolen machine hands over the wallet file, the labels you wrote and your full transaction history.

Sparrow helps: Argon2 encryption makes each password guess expensive, and a BIP39 passphrase means the seed words alone are not enough to rebuild the wallet.
Sparrow cannot: Rescue a weak password. An offline attacker gets unlimited attempts with no rate limit beyond the maths.

5. Coercion, or someone who knows you have coins

The uncomfortable one. Encryption is irrelevant when the attacker can simply demand the password, and public bragging is what creates the target.

Sparrow helps: Multisig splits spending authority across locations, so no single conversation moves the funds. Separate wallets let you keep a small, plausible balance apart from savings.
Sparrow cannot: Do anything about the fact that you talked. There is no duress wipe and no hidden panic mode. Multisig, step by step.

6. You, and the recovery phrase

The attacker who actually wins most often. A phrase photographed "temporarily", saved in a cloud note, typed into a website, or written once and stored where a flood found it.

Sparrow helps: It shows the words once, on your machine, and never transmits them. You can test the restore while the balance is still zero.
Sparrow cannot: Recover them. There is no reset, no identity check, no custodial fallback. Seed and passphrase setup.

Source: sparrowwallet.com — best practices

Is Sparrow a hot wallet or a cold wallet?

This is the most-searched question about Sparrow and the most badly answered. Sparrow is not inherently either. It is a signing and transaction-building program, and the answer depends entirely on where the private key sits while the program is running.

Assessment by this site, based on the keystore and signing options documented by the Sparrow project.
How you configure it	Where the private key lives	What an attacker on that computer can reach	Fair label
Software keystore on your everyday laptop	Encrypted wallet file on that same disk	The wallet file, plus anything you type while it is unlocked	Hot wallet
Software keystore on a machine you barely use	Encrypted wallet file, unlocked far less often	The file at rest — useless without the password	Hot, with friction
Hardware signer connected over USB	Inside the signing device, never exported	Your addresses and an unsigned transaction. Signing needs a button press on the device	Cold keys, online desk
Airgapped signer over QR codes or SD card	On a device that has never touched a network	Nothing signable. Data crosses the gap only when you carry it	Cold
Watch-only wallet from an xpub	Not on this computer at all	Your balance, history and future addresses — no spending authority	No keys present

What "watch-only" actually means here

A watch-only wallet is built from an extended public key — an xpub — or from an output descriptor, which is a small text recipe describing how addresses are derived. Either one lets Sparrow generate every address you will ever receive on, check balances and assemble a spend, without containing the secret needed to authorise it.

That is why an airgapped setup works. The online computer holds a watch-only wallet and produces a PSBT: a partially signed bitcoin transaction, a standard file format that carries everything the signer needs to know and nothing it needs to keep secret. You move the PSBT to the offline device by QR code or SD card, the device signs it, and the signed version comes back. The key never crosses the gap.

An xpub is not harmless, though. Anyone holding it can see your entire transaction history and every future address, forever. Treat it as sensitive information even though it cannot spend a single satoshi.

A workable default

Keep a small hot wallet for spending and a separate hardware-backed wallet for savings. Both live in one Sparrow installation as separate tabs. Once the savings balance is more than you would carry as cash, those keys belong on a dedicated device.

Which signing devices Sparrow supports covers USB, QR and SD card modes for each brand.

What the encryption actually buys you

Sparrow encrypts wallet files with Argon2, the algorithm that won the Password Hashing Competition in 2015, and the project deliberately tunes it so that deriving the key from your password takes at least 500 milliseconds on modern hardware. Argon2 is also memory-hard, which is the property that stops an attacker from getting an enormous speed-up simply by moving the work onto graphics cards.

In practice: every guess an attacker makes costs half a second of real work. Against a password with genuine entropy — five or six random words, or a long string from a password manager — the number of guesses required is large enough that half a second each puts the total beyond any budget. That is why an encrypted wallet file on a stolen laptop is usually not the end of the story.

What it does not buy you

Argon2 slows guessing down; it does not make a bad password good. Attackers do not try every combination, they try lists — the most common ten million passwords, leaked password dumps, and dictionary words with predictable substitutions. Something like bitcoin2026 or Satoshi!23 is already on those lists. Half a second per attempt, spread across a hundred parallel workers, chews through a ten-million-entry list in under a day. The cost per guess only helps when there are astronomically many guesses to make.

The other limit is scope. File encryption protects the file. It does nothing once the wallet is open on a compromised machine, and it does nothing at all about your seed backup, which is plaintext by definition. A metal plate in a drawer is not encrypted by Argon2 or anything else.

Macro photograph of metal keys, illustrating that a wallet password protects the file rather than the seed backup

Pick the password like this

Five or more random words from a dice list, or a long generated string you store in a password manager. Not a phrase you invented, not a name and a year, and never the same password you used anywhere else. Write the recovery words on paper separately — the password protects the file, the words rebuild the wallet.

Source: sparrowwallet.com — Argon2 encryption

Audited, or only auditable?

Almost every wallet page you read treats "open source" as a synonym for "verified by experts". It is not, and the gap between the two words is where a lot of misplaced confidence lives.

What is genuinely true of Sparrow: the complete source is published under the Apache 2.0 licence, the issue tracker and commit history are public, releases are covered by a signed manifest of file hashes, and because the source is public a build can be reproduced independently rather than trusted on faith. Anyone with the skill and the time can read exactly how keys are derived, stored and used, and can compare a downloaded binary against what the code should have produced.

What we cannot tell you: that a named third-party security firm has published an audit report on Sparrow. We are not aware of one, and we are not going to invent a firm, a date or a CVE number to make this page look more authoritative. There is also no bug bounty programme we can point you to. If you find a claim of a Sparrow audit somewhere, ask for the report itself — a real audit is a document with a scope, a date and a list of findings, not a badge on a marketing page.

Why the distinction matters to you

Auditable means the defect will be found eventually, by someone, and cannot be hidden by the vendor. Audited means a specific team looked on a specific date and wrote down what they found. Open source gives you the first guarantee, which is the more durable of the two but also the slower one. Closed-source wallets with a published audit have the opposite profile: a snapshot of scrutiny, then nothing you can check yourself.

Practically, this means your confidence in Sparrow should rest on things you can verify today — that the download matches the signed manifest, that the code is public, that the project has shipped consistently for years and documents its own limitations honestly — rather than on a certificate that does not exist.

Source: github.com/sparrowwallet/sparrow — source and issue tracker

Has Sparrow Wallet been hacked?

We are aware of no compromise of the Sparrow wallet software itself: no incident in which the released application stole keys, leaked seeds or was found to contain a backdoor. If that changes, it will be visible in a public repository and public issue tracker rather than buried.

The losses attached to the Sparrow name come from somewhere else entirely, and the distinction matters because it tells you where to spend your caution. People have been robbed by impostor apps and fake download sites — software that borrowed the name, the logo and the description, then asked for a recovery phrase. The wallet was not broken into. The victim was handed a convincing forgery and typed their words into it.

That is why "is Sparrow safe" is the wrong first question for most people. The dangerous moment is the download, and on mobile there is no safe download at all, because there is no official mobile build to find. Read the mobile app situation — it is the single highest-risk search anyone makes about this wallet.

Is Sparrow Wallet a scam?

No, and the reason people ask is instructive. A free wallet that asks for no account and no identity looks suspicious to anyone used to consumer finance apps, and the fake versions in app stores actively feed that suspicion. The real project takes no custody of funds, sells nothing, and publishes its own source. What is a scam is everything wearing its name that asks you to type twelve words into a form.

There is no Sparrow Wallet support number

This deserves its own heading because the search volume behind it is dangerous. There is no Sparrow phone line. No live chat widget. No support email that can look up your wallet. No official direct messages on any social platform. No remote-assistance session.

None of this is an oversight. A non-custodial wallet has nothing to support in the custodial sense: there is no account to unlock, no balance to adjust and no password to reset. Nobody at the project can see your wallet, so nobody can restore it.

Which means every "Sparrow support" agent who appears when you post a problem is a thief. The pattern is consistent: they reply within minutes of a public complaint, they are helpful and calm, and eventually they need your recovery phrase to "validate the wallet", or a remote-desktop session to "check the sync", or a small payment to "unlock" your funds. All three are theft, dressed as help.

Real help exists only on the project's own channels — the documentation, the FAQ and the public issue tracker linked from the official site — and it is public, slow and never involves your words.

Three sentences that mean you are being robbed

"Please confirm your 12 or 24 recovery words so we can restore access."
"Install this remote support tool so an engineer can see your screen."
"A small validation payment is required to release your balance."

Two-line seed rule

Your 12 or 24 recovery words are the wallet. Write them on paper, never in a photo, cloud note or password manager, and never type them into a website, chat window or "support" agent — nobody legitimate will ever ask for them.

The verdict

Sparrow is one of the more trustworthy pieces of software in this category, and that judgement rests on structure rather than reputation: it takes no custody, publishes its source under Apache 2.0, signs its releases, encrypts wallet files with a properly chosen algorithm, and is unusually direct about what it will not do for you. There is no published third-party audit, and we would rather say so than dress the absence up.

The risk in a Sparrow setup is almost never the code. It is a download you did not verify, a computer you cannot vouch for, a password from your own head, and a recovery phrase that exists in exactly one place — or worse, in a photo. Fix those four things and this is a genuinely strong self-custody position. Ignore them and no wallet on earth helps.

If you want the shortest useful next step: verify your copy against the signed manifest, then set the seed up properly while the balance is still zero.

Sparrow Wallet security questions

Is Sparrow Wallet safe to use?

The software itself is a reasonable choice: it is non-custodial, the source is public under Apache 2.0, releases are covered by a signed manifest, and wallet files are encrypted with Argon2. Whether your setup is safe depends on three things Sparrow cannot control — whether your computer is clean, whether you verified the download, and whether your recovery words exist only on paper. Most losses trace back to those three, not to the wallet code.

Is Sparrow Wallet open source?

Yes. Sparrow is released under the Apache 2.0 licence and the full source is published on GitHub, so anyone can read it, build it and compare their build against the release. That makes it auditable. It is not the same as saying it has been audited — see the audit section above for why the distinction matters.

Has Sparrow Wallet had a security audit?

We are not aware of a published third-party security audit report for Sparrow that we could point you to, and we will not pretend otherwise. What exists instead is open code, a signed release manifest, public issue tracking and years of review by people who use it with real money. Treat "open source" as auditable, not audited.

Is Sparrow Wallet a hot wallet or a cold wallet?

Both, depending on how you configure it. A software keystore on an internet-connected computer is a hot wallet. Pair Sparrow with a hardware signer over USB, or run it fully airgapped with QR codes or an SD card, and your private keys never exist on the online machine — Sparrow becomes the watch-only, transaction-building half of a cold storage setup.

Is Sparrow Wallet non-custodial, and is it really free?

Yes to both. Sparrow never holds your coins and has no accounts, no balances on a server and no password reset, because there is no database with your funds in it. It is free software funded by voluntary donations, with no paid tier and no in-app purchases. The trade-off is that nobody can restore access for you.

Has Sparrow Wallet ever been hacked?

We are aware of no compromise of the Sparrow wallet software itself. The thefts that carry the Sparrow name come from impostors: fake mobile apps and lookalike download sites that harvest recovery phrases from people who thought they were installing the real thing. Read the mobile app situation before you install anything called Sparrow on a phone.

What is the Sparrow Wallet support number?

There is none. No phone line, no live chat, no ticket desk, no official direct messages. Anyone who gives you a "Sparrow support" number, or contacts you first offering help, is running a theft. Legitimate help lives in the project documentation and the public issue tracker, and never involves your recovery words or remote access to your screen.

Self-custody starts after the purchase

Buy on a regulated platform, withdraw promptly to keys you control, and keep the long-term balance behind a hardware signer rather than an exchange login.

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