Question 1

What is a hash and what is it used for?

Accepted Answer

A hash is a fixed-length fingerprint of some input data, produced by a one-way function: the same input always yields the same hash, but you cannot reverse the hash back into the original data. Hashes are used to verify integrity — for example, a download page might publish the SHA-256 of a file so you can confirm your copy matches byte for byte — and to detect changes, since even a one-character edit produces a completely different hash. They also appear in version control, deduplication, and as building blocks inside other systems. This tool computes the common hashes of any text you type or any file you drop, so you can compare a value against a published checksum or generate one yourself.

Question 2

Which hash algorithm should I use?

Accepted Answer

For verifying downloads and general integrity checking, SHA-256 is the modern default: it is widely supported, fast, and has no known practical weaknesses. SHA-512 and SHA-384 produce longer digests and can be marginally faster on 64-bit systems; use them when a project specifies them. MD5 and SHA-1 are included because you will still encounter them — many older tools, package indexes and legacy checksums use them — but both are cryptographically broken: it is feasible to craft two different inputs with the same MD5 or SHA-1 hash. That makes them fine for non-security checks like detecting accidental corruption, but unsuitable for security decisions such as verifying that a file has not been tampered with by an attacker.

Question 3

Can I hash a file, not just text?

Accepted Answer

Yes. Click the upload area or drag a file onto it, and the tool reads the file's bytes in your browser and computes the selected hashes over the exact contents — the same value you would get from a command-line tool like sha256sum or certutil. This is the usual way to verify a download: compute the file's SHA-256 here and compare it to the checksum the publisher lists. The file is read locally and never uploaded; remove it with the clear button to go back to hashing typed text. Very large files take longer and use more memory because the whole file is loaded to hash it, but typical downloads and documents are handled quickly.

Question 4

Are MD5 and SHA-1 safe to use?

Accepted Answer

They are safe for non-adversarial uses and unsafe for security. Because researchers have demonstrated practical collision attacks — two distinct inputs that share the same hash — neither MD5 nor SHA-1 should be used to prove that a file is authentic or untampered, to store passwords, or in digital signatures. They remain perfectly useful for catching accidental changes: a corrupted download or a copy error will almost certainly change the MD5 or SHA-1, so comparing them still flags obvious problems. When the goal is security rather than error-detection, choose SHA-256 or stronger. This tool offers MD5 and SHA-1 mainly for compatibility with existing checksums you need to match.

Question 5

Is my text or file uploaded to a server?

Accepted Answer

No. All hashing happens entirely in your browser. SHA-1, SHA-256, SHA-384 and SHA-512 are computed with the built-in Web Crypto API, and MD5 with a small local JavaScript implementation; neither sends your data anywhere. Whether you type text or drop a file, the bytes never leave your device, nothing is logged, and there is no account or sign-up. That makes it safe to hash sensitive content, and it means the tool keeps working with no internet connection once the page has loaded. Closing or reloading the tab discards everything.

Question 6

Why does the same text give a different hash elsewhere?

Accepted Answer

Almost always it is a difference in the exact bytes being hashed. Hashes are computed over raw bytes, so an extra trailing newline, a space, a different text encoding (this tool uses UTF-8), or Windows versus Unix line endings will all change the result. When comparing against another tool, make sure both are hashing identical input — for files this is exact, but for text it is easy to include or omit a final newline. Also confirm you are comparing the same algorithm and the same case; this tool shows lowercase HEX by default with an uppercase toggle, but the underlying value is identical regardless of case.

Hash Generator

How to Generate a Hash

Enter text or drop a file

Pick your algorithms

Copy and compare

Frequently Asked Questions