SHA-256 Hash Generator
Compute the SHA-256 digest of any text — hex or base64 output, uppercase option, and hex/base64 input decoding. Runs entirely in your browser, no server, no sign-up.
About this tool
This SHA-256 hash generator computes the SHA-256 (SHA-2) digest of any text right in your browser. The hashing runs locally in WebAssembly — your input is never uploaded to a server, which makes it safe for passwords, keys, and other sensitive strings.
SHA-256 produces a fixed 256-bit (32-byte) digest. It is the most widely used cryptographic hash today: it secures TLS certificates, backs content-addressed storage and Git object IDs, anchors blockchain transactions, and is the standard choice for file-integrity and download checksums.
Options
- Interpret input as — hash the text as plain UTF-8 (default), or decode it from hex or base64 first so you can hash existing raw bytes such as a key or ciphertext.
- Output format — return the digest as 64-character hex (default) or as base64 (44 characters).
- Uppercase hex — emit the hex digest in uppercase.
Notes
- SHA-256 is a one-way function: a digest cannot be reversed back into the original text.
- The same input always produces the same digest, so SHA-256 is ideal for verifying that data has not changed.
- To hash an entire file (and also get MD5, SHA-1, SHA-512, and CRC-32), use the file-hash tool instead.
FAQ
Why does my hash differ from what another tool produced for the "same" input?
Almost always an invisible byte difference: a trailing newline or space, Windows
\r\n line endings, or the other tool hashing a file rather than the pasted text.
Check the Interpret input as setting too — deadbeef hashed as text digests
the eight ASCII characters, while hashed as hex it digests the four raw bytes,
and the results are completely different. The uppercase toggle only changes the
display, never the digest.
How do I hash raw bytes, like a key or ciphertext, instead of text?
Set Interpret input as to hex or base64. The input is then decoded to its
raw bytes first and the SHA-256 is computed over those bytes — which is what you
want when the value is a key, a random nonce, or another hash rather than
human-readable text.
Can a SHA-256 hash be reversed to reveal my original text?
No — SHA-256 is a one-way function; there is no algorithm that recovers the input from the 256-bit digest. The practical caveat: if the input was short or guessable (a common password, a dictionary word), an attacker can brute-force candidates and compare hashes. Which leads to…
Should I use SHA-256 for storing passwords?
No. SHA-256 is deliberately fast, which is exactly wrong for passwords — GPUs can test billions of guesses per second. Use a slow, memory-hard password hash instead: this site's argon2-hash tool generates Argon2id PHC strings designed for that job. SHA-256 is the right choice for checksums, content addressing, and integrity verification.
Developer & Automation Access
Run it from the terminal
Same engine as this page, headless — via the gizza CLI:
gizza tool sha256-hash "Hello, world!"New to the CLI? Get gizza →
Open it by URL
Pre-fill and auto-run this tool with query parameters — the names match the API/CLI:
https://gizza.ai/tools/sha256-hash/?text=Hello%2C%20world%21&input_encoding=text&output_format=hex&uppercase=trueMachine-readable descriptor: tool.json — title + parameters JSON Schema for agents.