What is a cryptographic hash?
A hash function takes any input — a word, a file, a whole document — and produces a fixed-length string of characters called adigest. The same input always yields the same digest, but even a one-character change produces a completely different result, and you cannot reverse a digest back into the original text. That makes hashes ideal for verifying that data has not been altered, comparing files, building checksums and storing fingerprints of content.
How to use this tool
- Type or paste your text into the input box.
- Pick an algorithm — SHA-256 is the right default for most uses.
- The hex digest appears instantly and recomputes as you type, or press Generate hash.
- Copy the result with one click to paste it wherever you need it.
Which algorithm should I choose?
SHA-256 is the modern workhorse — fast, secure and used everywhere from TLS certificates to blockchains and Git.SHA-384 and SHA-512 produce longer digests for stricter security requirements and are often paired with larger keys. SHA-1 is included only for inspecting older systems and legacy checksums; it is no longer considered collision-resistant, so avoid it for new security-sensitive work. We deliberately do not offer MD5: it is cryptographically broken — attackers can generate colliding inputs in seconds — so it is unsafe for integrity or security and would give a false sense of protection.
Is it private?
Yes. This tool uses your browser's built-in Web Crypto API (crypto.subtle.digest) to compute every hash locally on your device. Nothing you type is sent to a server, logged or stored, which means it is safe to hash passwords, API tokens, recovery phrases and other sensitive strings without them ever leaving your computer.
Frequently asked questions
Can I get the original text back from a hash?
No. Hashing is one-way by design — you can verify a known value by re-hashing it, but you cannot reverse a digest into its input.
Why does the same text always give the same hash?
Hash functions are deterministic. Identical input always produces an identical digest, which is exactly what makes them useful for verifying data.
Is this safe for passwords?
It is safe in the sense that nothing is uploaded. Note that for storing user passwords you should use a slow, salted password hash (like bcrypt or Argon2) rather than a raw SHA digest.