How do I identify a hash?
Paste the hash and this tool ranks the most likely algorithms from its length, character set and any prefix. A 32-character hex string points to MD5, NTLM or MD4, while a $2b$ prefix means bcrypt. It runs entirely in your browser and nothing is uploaded.
What hash identification can and cannot tell you
A hash is a fixed-length fingerprint of some data, produced by running that data through a one-way function. The catch for anyone looking at a stray hash is that the output carries no label. A 64-character run of hex could be SHA-256, SHA3-256 or several others, and nothing in the string itself says which. What you can do is measure the shape: how long it is, which characters it uses, and whether it starts with a tell-tale prefix. That narrows the field, often to a single strong candidate, but it is a ranked guess rather than proof.
This tool does that measuring for you. Paste a hash and it reports the length, the character set, and a list of algorithms that produce strings of exactly that shape, most likely first. It never contacts a server, so it is safe to use with hashes pulled from a real database.
Where identifying a hash is genuinely useful
The legitimate uses are everyday. A developer inheriting an old system needs to know whether stored passwords are unsalted MD5 (a problem to fix) or bcrypt (fine to keep). A security team triaging a leaked file wants to know what they are dealing with before choosing tools. A forensics analyst logs the likely algorithm as part of documenting evidence. In each case the first question is simply what is this, and the shape of the string answers most of it.
Knowing the algorithm also tells you how worried to be. MD5 and SHA-1 are broken for security and should not guard passwords, while a slow, salted scheme like bcrypt or Argon2 is doing its job. The prefix on the modular crypt formats makes those easy: they literally begin with a code for their own scheme.
Why the same shape fits several algorithms
Hash length is set by the output size in bits, not by the algorithm's name. MD5, MD4 and NTLM all output 128 bits, which is 32 hexadecimal characters, so they are indistinguishable by shape alone. The same is true at 160 bits (SHA-1 and RIPEMD-160) and at 256 bits (SHA-256, SHA3-256 and others). Ranking uses how common each one is in the wild: MD5 leads the 32-hex group, SHA-256 leads the 64-hex group. Context you already have, such as where the hash came from, usually settles the rest.
Reading the examples
The lengths below were counted by hand and match what this tool reports. Everything runs in your browser, so nothing you paste leaves your device.
Count the characters yourself and the pattern is clear: 32 for the 128-bit family, 64 for the 256-bit family, and a self-describing prefix for bcrypt. That is exactly the logic this tool applies, only faster.
How we work it out
It measures the string length, detects the character set (hexadecimal, Base64 or a modular crypt format), reads any dollar-sign prefix, and matches all three against a table of known hash shapes, returning the candidate algorithms most likely first.
Frequently asked questions
Can this tell me exactly which algorithm made a hash?
No, and nothing can from the hash alone. A raw digest is just a run of characters with no label attached. This tool works out which algorithms produce a string of that length and character set, and ranks them by how common they are, but several algorithms share the same shape so the top guess is not a guarantee.
Why do MD5, NTLM and MD4 all show for one hash?
Because they all produce 128-bit output, which is 32 hexadecimal characters. From the shape alone they are indistinguishable. MD5 is by far the most common, so it is ranked first, but a 32-hex string from a Windows password dump is far more likely to be NTLM. Context tells you which, the string cannot.
Can it crack or reverse a hash?
No. Identifying the likely algorithm is a completely separate step from recovering the original input, which this tool does not attempt and, for a strong hash, is not feasible. Knowing the algorithm just tells you which tool you would need, and whether the hash is a weak one like MD5 or a slow password hash like bcrypt.
What does the $6$ or $2b$ at the start mean?
That is a modular crypt format prefix, and it is the most reliable clue there is. $2a$, $2b$ and $2y$ mean bcrypt, $6$ means sha512crypt (common in Linux /etc/shadow), $5$ means sha256crypt, $1$ means md5crypt, and $argon2id$ means Argon2. Unlike a bare hex digest, these strings name their own scheme.
Is the hash I paste sent anywhere?
No. The identification happens entirely in your browser with JavaScript. The hash you paste stays on your device and is never uploaded or logged, which matters because hashes often come from sensitive sources like password databases.