Hash Generator Online Free
Generate MD5, SHA-1, SHA-256, SHA-384, and SHA-512 hashes from any text or file instantly. No signup, runs entirely in your browser — your data never leaves your device.
Type or paste text above — all five hashes appear instantly.
How the Hash Generator Works
- 1Choose Text Input to hash a string, or File Hash to compute the checksum of any file on your device.
- 2For text, type or paste into the box — all five hashes update live as you type. For files, drag and drop or click to browse.
- 3Each algorithm row shows its hash digest. Click Copy next to any algorithm to copy just that hash, or Copy all to copy all five at once.
- 4To verify a file checksum, compare the hash shown here with the value published by the file's author — they must match exactly, character for character.
Which Hash Algorithm Should You Use?
For any new security-sensitive application, use SHA-256 as the default. It is widely supported, fast, and provides 128 bits of collision resistance — more than sufficient for the foreseeable future. SHA-512 offers a larger safety margin and can be faster than SHA-256 on 64-bit CPUs due to wider internal registers.
Avoid MD5 and SHA-1 for anything security-related. Both are broken against collision attacks: an attacker can craft two different inputs that produce the same hash. For non-security uses — detecting accidental file corruption, de-duplicating cache entries, generating stable IDs for content-addressed storage — MD5 and SHA-1 remain fast and practical because a deliberate adversary is not involved.
Tips for Working with Hash Values
Always compare the full hash
When verifying a downloaded file, compare all 64 characters of a SHA-256 hash — not just the first few. Partial matches are meaningless; even one different character means the file does not match.
Case does not matter
Hex hash digests use the digits 0–9 and letters a–f. Uppercase (A–F) and lowercase (a–f) represent the same value. This tool outputs lowercase, which is the most common convention, but comparison against uppercase hashes is still valid.
Hash passwords with a KDF, not SHA
Never hash passwords directly with SHA-256 or MD5. Use a dedicated key derivation function (KDF) like bcrypt, scrypt, or Argon2, which add salting and intentional slowness to prevent brute-force attacks. SHA and MD5 are far too fast for password storage.
Verify download integrity
After downloading software, ISOs, or large files, check the SHA-256 checksum against the value published on the official site. This confirms the file arrived intact and was not tampered with in transit or on the download server.
Hashing encodes, not encrypts
Hashing is a one-way function — you cannot recover the original input from a hash. If you need to reverse the transformation (i.e., decrypt), you need encryption (AES, RSA), not hashing. Use Base64 for reversible encoding of binary data.
Identical files always produce identical hashes
If two files produce the same SHA-256 hash, they are byte-for-byte identical with overwhelming probability (a deliberate SHA-256 collision has never been demonstrated publicly). This makes hash comparison a reliable way to de-duplicate files.
Frequently Asked Questions
What is a cryptographic hash and what is it used for?
A cryptographic hash function takes any input (text, file, binary data) and produces a fixed-length output called a digest or hash. Even a tiny change to the input produces a completely different hash. This makes hashes useful for verifying file integrity (checking a downloaded file matches its published checksum), storing passwords securely, and as building blocks in digital signatures and certificates.
What is the difference between MD5, SHA-1, SHA-256, SHA-384, and SHA-512?
All five are hash algorithms, but they differ in security and output length. MD5 produces a 128-bit (32 hex character) digest and is now considered cryptographically broken — collisions can be generated deliberately. SHA-1 produces 160 bits and is also deprecated for security uses. SHA-256 (256 bits), SHA-384 (384 bits), and SHA-512 (512 bits) are members of the SHA-2 family and remain secure for current use. SHA-256 is the most widely deployed; SHA-512 offers a larger safety margin.
How does the hash generator work in the browser?
SHA-1, SHA-256, SHA-384, and SHA-512 hashes are computed using the browser's built-in Web Crypto API (window.crypto.subtle.digest), which is implemented in native code and available in all modern browsers. MD5 is computed using a pure JavaScript implementation of RFC 1321, since the Web Crypto API does not include MD5. For files, the FileReader API reads the file as an ArrayBuffer in memory before hashing — the file is never uploaded.
Is my text or file sent to a server?
No. Everything happens inside your browser. Text is encoded to bytes using the TextEncoder API, and files are read using FileReader. Neither is transmitted anywhere. You can disconnect from the internet after the page loads and the tool will still work correctly.
Should I still use MD5 or SHA-1?
Not for security-sensitive purposes. MD5 and SHA-1 are vulnerable to collision attacks — meaning two different inputs can be crafted to produce the same hash. They should not be used for password hashing, code signing, or TLS certificates. They are still fine for non-security uses like detecting accidental file corruption or generating cache keys, where a malicious actor is not trying to forge a collision.
What is a file checksum and how do I verify one?
A checksum is the hash of a file published by the file's author alongside the download. To verify a downloaded file, switch to the File Hash tab, drop the downloaded file in, and compare the SHA-256 (or whichever algorithm the publisher used) with the published value. If they match character-for-character, the file is intact. If even one character differs, the file has been modified or corrupted.
Why does the same text always produce the same hash?
Hash functions are deterministic — given the same input, they always produce the same output. This determinism is what makes them useful for verification. "Hello" will always hash to the same SHA-256 value. However, adding a single space or changing one letter completely changes the hash — a property called the avalanche effect.
What is the maximum file size the tool can handle?
The file is loaded entirely into browser memory before hashing, so the practical limit is determined by available RAM — typically several hundred megabytes to a few gigabytes on modern devices. Very large files (multi-GB video files, disk images) may cause the tab to run out of memory. For those, a command-line tool like sha256sum (Linux/macOS) or Get-FileHash (Windows PowerShell) is more appropriate.