Question 1

What is a cryptographic hash function?

Accepted Answer

A cryptographic hash function takes any input and produces a fixed-length output (the hash). The same input always produces the same hash, but even a single character change produces a completely different result — a property called the avalanche effect. Hashes are one-way: you cannot reconstruct the original input from the hash.

Question 2

What is the difference between MD5, SHA-1, SHA-256, and SHA-512?

Accepted Answer

MD5 produces a 128-bit hash and SHA-1 a 160-bit hash — both are fast but cryptographically broken and should not be used for security. SHA-256 (256-bit) and SHA-512 (512-bit) are part of the SHA-2 family and are considered secure for digital signatures, TLS certificates, and password hashing.

Question 3

Is MD5 safe to use?

Accepted Answer

MD5 is cryptographically broken — collision attacks are feasible, meaning two different inputs can produce the same hash. It should never be used for security purposes such as password storage or digital signatures. However, it is still widely used for non-security checksums like verifying file downloads, where speed matters more than collision resistance.

Question 4

Are my files uploaded when I use the File tab?

Accepted Answer

No, your files are never uploaded anywhere. The File tab uses the browser's built-in FileReader API to read your file entirely in local memory. Nothing is transmitted over the network — not to our servers or any third party. The hashing itself runs through the Web Crypto API, a secure native browser feature. Your file content stays completely on your device from the moment you drop it to the moment you close the tab.

Question 5

What is HMAC?

Accepted Answer

HMAC (Hash-based Message Authentication Code) combines a hash function with a secret key. It produces an output that verifies both data integrity (the message was not tampered with) and authenticity (it came from someone who knows the key). HMAC-SHA256 is widely used for API request signing, JWT tokens, and webhook verification.

Question 6

How do I verify a file download with a checksum?

Accepted Answer

Drop your downloaded file into the File tab, then check the published hash algorithm (usually SHA-256 or MD5) used by the software provider. Copy the hash shown next to that algorithm and paste it into the Verify Hash field. A green Match badge confirms your file is authentic and unmodified.

Question 7

What is Base64 encoding for hashes?

Accepted Answer

A hash is fundamentally a sequence of raw bytes. Hex encoding represents each byte as two characters (0-9, a-f). Base64 encoding represents those same bytes using 64 printable characters, producing a shorter string. Base64 hashes are commonly used in HTTP headers, HMAC signatures, JWT tokens, and some API authentication schemes.

Hash Generator

Verify Hash

Why Use Our Hash Generator?

How to Hash Text or a File

Frequently Asked Questions