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Guide
About the Hash Generator
A cryptographic hash function takes any input — a word, a document, a multi-gigabyte file — and produces a fixed-length “fingerprint” called a digest. The same input always produces the same digest, but even a one-character change produces a completely different result, and you cannot work backwards from the digest to the original input. That makes hashes ideal for verifying integrity (has this file changed?) and for checksums.
This tool computes MD5, SHA-1, the SHA-2 family, SHA-3, Ethereum's Keccak-256 and CRC32 entirely in your browser, so nothing you hash is ever uploaded. Hash typed text or raw bytes, or drop in any number of files to get their checksums, a ready-made sha256sum file, and Subresource Integrity values for script and stylesheet tags.
Which algorithm should I use?
For anything security-related, use SHA-256or stronger — it's the modern default and is used everywhere from TLS certificates to Bitcoin. SHA-512 produces a longer digest and can be faster on 64-bit hardware. SHA-1 is included for compatibility with legacy systems (like older Git object IDs) but is cryptographically broken and should not be used for new security purposes, and MD5 is thoroughly broken — both remain useful only as checksums against accidental corruption, and to match systems that still publish them. SHA-3is a different design kept as a backup to SHA-2; note that Ethereum's Keccak-256 is the pre-standard version and gives different results from SHA3-256.
Hashing is one-way — it is not encryption
You can't “decrypt” a hash back into the original data, because hashing throws information away by design. This is exactly why password databases store hashes rather than plain passwords. If you need to protect data so it can be recovered later, you want encryption (such as AES), not hashing.
Why does my hash not match the command line?
Almost always because the bytes differ. echo hello | sha256sum hashes “hello” plus a newline; use echo -n, or tick “Add a trailing newline” here to match. Text copied from Windows may carry CRLF line endings, which the line-ending option normalises. And a hash of a file's contents never matches a hash of its name.
How to use it
- 1Type or paste text, or drop in one or more files.
- 2Choose the algorithms (SHA-256 is a safe default).
- 3Choose hex or Base64 output.
- 4Copy the digest — or compare it against a published checksum to verify a download.
Frequently asked questions
What can I use a hash for?
Common uses are verifying that a downloaded file was not corrupted or tampered with (by comparing checksums), deduplicating data, and building integrity checks. Combined with a salt, hashes also underpin password storage.
Should I still use MD5?
Only as a checksum against accidental corruption, or to match a site that still publishes MD5 sums. It is cryptographically broken — two different files can be made to share an MD5 — so use SHA-256 for anything security-related.
How do I verify a download against a checksum file?
Switch to Files, drop in the downloads, and paste the contents of the SHA256SUMS (or .md5) file into Verify. Each file is marked as matching or not. BSD-style lines such as “SHA256 (file.zip) = …” work too.
What is an SRI hash?
Subresource Integrity lets a browser check that a script or stylesheet from a CDN has not been altered: <script src="…" integrity="sha384-…" crossorigin="anonymous">. Drop the file in and copy the SRI line.
Can two different files ever have the same hash?
In theory yes (a collision), but for SHA-256 and above the odds are astronomically small and no practical collision is known. That is why matching hashes are treated as strong evidence that two files are identical.
Does hashing a large file upload it anywhere?
No. The file is read and hashed locally in your browser via the Web Crypto API. Nothing leaves your device.
What is the difference between hex and Base64 output?
They are just two encodings of the same digest bytes. Hex is longer but ubiquitous for checksums; Base64 is more compact and common in tokens and HTTP headers.