Generate SHA-256 cryptographic hash digests from text or file input using the WebCrypto API.
This tool computes the SHA-256 digest of whatever you give it: text typed into a box, or the raw bytes of a selected file. It runs entirely in the browser on the WebCrypto API, so nothing you hash is uploaded anywhere. SHA-256 returns exactly 64 lowercase hexadecimal characters for any input, from an empty string to a multi-gigabyte file, and the same input always returns the same digest. The thing users most often get wrong: pasting text and hashing a file containing that same text usually produce different digests, because the file contributes encoding bytes, line endings, and possibly a byte-order mark that the text box does not.
A concrete input and expected output from the current implementation.
Input
abc
Expected output
ba7816bf8f01cfea414140de5dae2223b00361a396177a9cb410ff61f20015ad
SHA-256 of the three bytes 0x61, 0x62, 0x63. The value is the published FIPS 180-4 test vector for "abc", so it doubles as a self-check: any correct SHA-256 implementation returns exactly this digest.
Typed text is encoded to UTF-8 bytes and hashed; a selected file is read as raw bytes and hashed unchanged, so a byte-order mark, CRLF line endings, or a trailing newline all change the result. The WebCrypto API's digest operation performs the computation, and the resulting 32-byte digest is rendered as 64 lowercase hexadecimal characters.
SHA-256 involves no key, salt, or randomness, so identical input always yields the identical digest, and the input cannot be recovered from the digest. Finding two different inputs that collide is believed to require on the order of 2^128 attempts, which is why a matching digest is treated as strong evidence the bytes are identical.
No. SHA-256 is a one-way function, and no algorithm reverses it. The only way to "recover" an input is to guess candidates (dictionary words, brute-force strings) and hash each one until a digest matches, which is practical only for short, predictable inputs such as weak passwords.
Most likely a byte-level difference: the other tool appended a trailing newline, encoded the text as UTF-16, or hashed a file whose line endings differ from yours. SHA-256 is deterministic, so identical bytes always produce the same digest; compare the exact bytes each tool hashed rather than the visible text.
The example and behavioral notes were checked against the browser implementation. Standards and primary references below define the relevant format, formula, or platform behavior.
Generate strong, random passwords with customizable length, character sets, and complexity requirements.
Analyze password strength with entropy scoring, crack-time estimates, and improvement suggestions.
Create cryptographically random strings for API keys, tokens, salts, and unique identifiers.
Create QR codes for URLs, text, Wi-Fi credentials, vCards, and more with customizable size and colors.
Scan and decode QR codes from uploaded images or your device camera to extract embedded data.
Compute MD5, SHA-1, SHA-256, and SHA-512 checksums to verify file integrity and detect tampering.