How to Generate and Verify a Hash
A hash is a fixed-length fingerprint of some data. Change a single bit anywhere in a hundred-megabyte file and the hash changes completely — which is exactly what makes it useful for confirming that a download arrived intact and unmodified. This tool computes the six algorithms you actually encounter, works on text as you type and on files of substantial size, and lets you paste a published checksum to check it in one step.
Choose text or a file
Text hashes update live as you type. Files are read in chunks, so large ones do not exhaust memory.
Pick your algorithms
Several at once if you like. SHA-256 is the modern default; MD5 is still what most download pages publish.
Copy or verify
Click any hash to copy it, or paste an expected checksum to have it compared automatically.
Which Algorithm Should You Use?
SHA-256 is the right default for anything where the answer matters. It is the standard for software distribution, certificate signing and blockchain, and no practical attack against it exists. SHA-512 is stronger still and is actually faster on 64-bit processors, though the extra length is rarely necessary.
MD5 and SHA-1 are cryptographically broken and this matters more than most people assume. Researchers can construct two different files with the same MD5 hash cheaply, and the same has been demonstrated for SHA-1. That means a matching MD5 proves the file was not corrupted in transit, but does not prove nobody deliberately substituted it. They remain here because they are still what an enormous number of download pages publish, and checking is better than not checking.
CRC32 is not a hash at all— it is a checksum, designed to catch accidental corruption in a network transfer or a ZIP archive. It is fast and tiny, and trivially easy to forge deliberately. Use it to detect a bad copy, never to establish that a file is genuine.
Why Doing This in Your Browser Matters
Online hashers see everything you paste
A tool that hashes on a server receives your input in full. People routinely paste passwords, API keys and private documents into these. Here, nothing is transmitted.
Large files never leave your machine
Uploading a two-gigabyte ISO just to check its checksum is absurd, and slow. Reading it in chunks locally takes seconds and uses no bandwidth.
It works offline
Once the page has loaded, hashing needs no network at all. Useful on an air-gapped machine or a poor connection.
Hashing is not encryption
A hash is one-way and cannot be reversed. Sites offering to decrypt an MD5 are looking it up in a table of pre-computed common inputs, which is why weak passwords fall instantly.
Frequently Asked Questions
How do I check the MD5 or SHA-256 of a file?
Switch to the file tab, drop the file in, and press Compute. Reading happens in chunks, so even large files work without exhausting memory.
Is my file or text uploaded to a server?
No. Everything is computed inside your browser, which matters because people routinely paste passwords and private data into online hashers.
Which hash algorithm should I use?
SHA-256 for anything security related. MD5 and SHA-1 only when checking against a published checksum that uses them.
Is MD5 still safe to use?
Not for security. Two different files can be constructed with the same MD5 cheaply, so a match proves the file is uncorrupted but not that it is authentic.
What is the difference between a hash and a checksum?
A checksum like CRC32 catches accidental corruption and is easy to forge. A cryptographic hash is designed so that finding two inputs with the same output is computationally infeasible.
How do I verify a download?
Hash the file here, then paste the checksum from the download page into the verify box. It is compared against every hash computed.
Can a hash be reversed to get the original data?
No. Hashing is one-way. Sites claiming to decrypt hashes are looking the value up in a table of common inputs, which only works for weak passwords.
Why is there a size limit on SHA hashing?
The browser cryptography API has no streaming interface, so SHA variants need the whole file in memory. CRC32 and MD5 are computed in chunks and have no such limit.
Why do two files with the same name have different hashes?
Because their contents differ, even if only by a byte of metadata. That sensitivity is the entire point of a hash.
Does whitespace change a text hash?
Yes, completely. A trailing space or a different line ending produces an entirely different hash, which catches people out when comparing text.
Can I compute several hashes at once?
Yes. Select any combination of algorithms and they are all computed from the same input in one pass.
Is this hash generator really free?
Completely free, with no limits, no signup and no premium wall. Everything runs in your browser.
Last updated: July 21, 2026 · FlipMyFormat Hash Generator
Written and maintained by the FlipMyFormat team