Hashes/Crypto
Scrypt Hash + Verify
Hash passwords with scrypt (RFC 7914, memory-hard KDF), with verification against an existing hash.
Scrypt (RFC 7914) was one of the first memory-hard password-hashing algorithms: it deliberately requires a lot of RAM, not just CPU time, to make parallel brute-forcing on GPUs and ASICs harder.
How to use it
- Hash: enter a password and tune the parameters (N — memory cost, r — block size, p — parallelism) to get a hash.
- Verify: paste a password and an existing scrypt hash to check whether they match.
- Every hash uses a fresh random salt, so the same password produces a different hash each time.
Common uses
- Checking that a backend correctly hashes passwords with scrypt before storing them.
- Generating a test scrypt hash for fixtures or seed data during development.
- Comparing scrypt against bcrypt and Argon2 when choosing a hashing algorithm for a new project.
Things to keep in mind
The N parameter (memory cost) increases both required memory and compute time exponentially — tune it to your server's actual capacity.
Scrypt has been superseded by Argon2 (the official Password Hashing Competition winner) as the recommended choice for new systems, though scrypt itself still isn't considered unsafe.
Article about this tool: Scrypt: why the algorithm needs so much memory
Frequently asked questions
How does scrypt differ from bcrypt or PBKDF2?
Scrypt is deliberately memory-hard as well as CPU-intensive, making it far more expensive to crack using GPUs or custom ASIC hardware compared to bcrypt or PBKDF2, which mainly resist CPU-based brute-forcing.
What do the N, r, and p parameters control?
N sets the CPU/memory cost (must be a power of two), r sets the block size affecting memory use per operation, and p sets parallelization — increasing any of them raises the resource cost of both legitimate use and attacks.
Is scrypt still a good choice compared to Argon2?
Scrypt remains solid and battle-tested, but Argon2 (the winner of the Password Hashing Competition) is generally recommended for new systems, since it offers more fine-grained control over memory and side-channel resistance.
How much memory does scrypt actually consume?
Approximately 128 × N × r bytes per computation. With typical parameters (N=16384, r=8) that's about 16 megabytes per hash — negligible for a single login, but significant at thousands of concurrent authentications on a server.
Where else is scrypt used besides password hashing?
Scrypt is known as a proof-of-work algorithm in some cryptocurrencies (Litecoin, for example) — it was chosen specifically for its resistance to mining on specialized ASIC hardware, unlike Bitcoin's SHA-256.