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SHA-256 is the standard. All client-side via Web Crypto API.
Your text never leaves the browser.
A cryptographic hash function takes arbitrarily long text and produces a fixed-length fingerprint — the hash. The key property: even the slightest change in input (a single bit) produces a completely different hash (avalanche effect).
SHA-256 (Secure Hash Algorithm, 256 bits) is the most widely used hash algorithm worldwide. It forms the foundation for TLS/SSL certificates, Bitcoin mining, digital signatures, and password hashing. A SHA-256 hash is 64 characters long (hexadecimal) and is currently considered collision-resistant.
SHA-512 operates with 512 bits and 64-bit words — optimized for 64-bit processors. The hash is 128 characters long. SHA-512 is preferred in security-critical systems (military, finance, long-term archiving).
MD5 (128 bits) and SHA-1 (160 bits) are considered cryptographically broken — collisions have been demonstrated. Nevertheless, they remain widespread: MD5 for file integrity checks, SHA-1 in older Git repositories.
Hash computation happens entirely client-side in your browser via the Web Crypto API (crypto.subtle.digest) — no text is sent to a server, nothing is stored.
The classic case: you just downloaded a Linux ISO or a software package and want to make sure the file really is what the vendor published — not a corrupted download, not a tampered mirror. Or you have the same file twice, once from a USB stick and once from a backup, and you wonder whether they are identical. A hash answers both questions: compute the SHA-256 value of both files and compare. Here you get MD5, SHA-1, SHA-256, and SHA-512 entirely in your browser — no installation, no upload.
Select SHA-256 in the dropdown — it is what most vendors use for download checksums.
Paste your text, or copy the content of small files directly into the field. For large files (ISO, installer) compute the hash locally — e.g. with sha256sum file.iso on Linux or Get-FileHash in PowerShell — and paste it here to compare.
Click “Hash” and compare the result character by character with the checksum on the vendor's download page. If they match, your download is intact.
A hash is a one-way street: “Hello” becomes a fixed 64-character string, but the string never becomes “Hello” again. Encryption, by contrast, is reversible — with the right key you get the plaintext back. Hashes are therefore perfect for integrity checks and password storage: the database stores only the hash of your password, and on login the entered text is hashed and compared. Important: never use MD5 or SHA-1 for passwords — they are considered broken. Use slow, password-specific algorithms like bcrypt or Argon2 instead.
SHA-256 is the standard for downloads, certificates, and signatures — when a vendor publishes a checksum, it is almost always SHA-256. SHA-512 is the 64-bit variant: on 64-bit systems often slightly faster and with double the output length — a good fit for long-term archiving. MD5 and SHA-1 are cryptographically broken — proven collisions exist where two different files produce the same hash. For internal consistency checks (“did the file change since yesterday?”) they are fine; for security, never.
No. A hash cannot be “decrypted” — there is simply no way back. What attackers do instead: try weak passwords with rainbow tables or wordlists and compare the hashes. That is exactly why passwords need slow, salt-based algorithms instead of plain SHA-256.
Because the output length is fixed: 256 bits, i.e. 64 hexadecimal characters — no matter whether you hash “a” or an entire disk. That is the definition of a hash function: arbitrary input, fixed output.
No. The computation runs entirely locally in your browser via the Web Crypto API (crypto.subtle.digest). Nothing is sent to a server, nothing is logged, nothing is stored.
Base64 is a reversible encoding: you can decode the text at any time. A hash is a one-way street — the output never yields the input. If you need Base64, the matching encoder/decoder is right here.
Recommendations on hash algorithms come from NIST (FIPS 180-4, SHA-2 family) and BSI (TR-02102-1). Our blog post Encoding vs. Hashing vs. Encryption explains the difference between encoding, hashing, and encryption. And to decode Base64 data: Base64 Encoder/Decoder.