Hash Generator
Generate a cryptographic hash of text or a file, using your browser’s own crypto engine.
Processed on your device — no upload
SHA-256 and SHA-512 come from your browser's Web Crypto engine. MD5 and SHA-1 are implemented here because published checksums still use them — both are broken for security and are offered only for verifying legacy downloads.
How to use it
- Type text, or choose a file.
- All five hashes are computed at once.
- Tap any result to copy it.
How it works
A cryptographic hash turns any input into a fixed-length fingerprint. The same input always gives the same output; changing a single bit changes roughly half the output bits; and the function cannot be run backwards to recover the input.
SHA-256, SHA-384 and SHA-512 come from the Web Crypto API, which is the browser's own implementation — the same code used for HTTPS, running natively rather than in JavaScript.
MD5 and SHA-1 are broken, and they are here anyway. Both have practical collision attacks: two different files can be constructed with the same hash, which defeats the entire purpose for signatures and integrity. Neither is in the Web Crypto API, deliberately. MD5 is implemented here in JavaScript because a great deal of software still publishes MD5 checksums, and verifying a legacy download is a legitimate need.
Use SHA-256 for anything new. Use MD5 or SHA-1 only to check a value someone else already published.
A worked example
Type hello and look at the SHA-256 result. Now change it to Hello — one capital letter — and the entire hash is different. Nothing about the new value hints that the input was almost the same. That property, the avalanche effect, is what makes a hash useful for detecting change.
The practical case is file verification. You download a 4 GB Linux ISO and the project publishes a SHA-256 checksum. Choose the file here, compare the SHA-256 row against the published value, and if they match the download is byte-identical to what was released.
The file is read into your browser to be hashed and goes nowhere. That matters: uploading a 4 GB file to a website to check its integrity is slower than downloading it again, and hands a copy to a stranger.
What hashing is not. It is not encryption — there is no key and no way back. It is also not a safe way to store passwords on its own: a plain SHA-256 of a password can be reversed with a lookup table in seconds. Password storage needs a deliberately slow function with a salt, such as bcrypt, scrypt or Argon2. If you are hashing passwords with SHA-256, that is a bug.
To protect a message rather than fingerprint it, encryption is the tool you want.
Questions
Can it produce a SHA512 digest?
Yes. SHA-256, SHA-384 and SHA-512 all come from your browser's own crypto engine, alongside MD5 and SHA-1 for checking legacy checksums.
Is my file uploaded?
No. It is read into your browser and hashed there. For a large ISO that is also far faster than any upload could be.
Which algorithm should I use?
SHA-256 for anything new. It is the current standard, fast, and has no known practical weaknesses.
Why are MD5 and SHA-1 marked as broken?
Both have practical collision attacks — two different inputs can be made to produce the same hash. They are included only for checking checksums that others have already published.
Can a hash be reversed?
Not by computation. But a short or common input can be found by looking it up in a precomputed table, which is why hashing alone is not enough for passwords.
Should I hash passwords with SHA-256?
No. Password storage needs a deliberately slow, salted function such as bcrypt, scrypt or Argon2. SHA-256 is fast, which is exactly wrong for that purpose.
Why is my hash different from another tool’s?
Usually a trailing newline. A text file almost always ends with one and a text box does not, and that one byte changes the entire hash.
What is the difference between hashing and encryption?
Encryption is reversible with the key; hashing is one-way by design. A hash proves something has not changed; encryption keeps it secret.
Is there a file size limit?
No fixed limit, though the file is read into memory. Multi-gigabyte files are fine on a laptop and may fail on a phone.
Related Security tools
Password Generator
Strong passwords and passphrases
open$termiva pass --checkPassword Strength Checker
How long it would take to crack
open$termiva uuid --count 10UUID Generator
Version 4 identifiers in bulk
open$termiva base64 --encodeBase64 Encoder and Decoder
Encode and decode, both ways
open