SHA-256 Checksum Generator

This tool calculates a repeatable digest for a text input so users can compare whether two inputs produce the same SHA-256 output.

Designed for: Developers and analysts comparing text fixtures or learning about message digests.

How to use this tool

Enter text and choose Calculate. The browser encodes the input as UTF-8 and asks the Web Crypto API for a SHA-256 digest, which is displayed as lowercase hexadecimal.

How the result is produced

The tool uses crypto.subtle.digest with SHA-256 and converts the returned ArrayBuffer into hexadecimal bytes. A digest is not reversible encryption and does not prove who created an input.

Test examples

The same text and encoding produces the same digest. A one-character change produces a different digest. The result depends on the exact bytes, including whitespace and line endings.

Limitations

This is a text checksum demonstration. It does not hash files, provide password storage, create a digital signature, or establish authenticity. Do not use a plain digest as a password-storage scheme.

Privacy and processing

The text is encoded and hashed in the browser with Web Crypto. It is not sent to the server by this tool.

Related guide

Checksums, hashes, and signatures: do not confuse their jobs

Related tools in this category

• JSON Formatter and ValidatorPaste a JSON object or array, then format it or validate its syntax.
• Base64 Encoder and DecoderChoose encode or decode. The browser performs the conversion locally.
• Unix Timestamp ConverterConvert a date-time to Unix seconds or convert seconds back to an ISO-style date.

Documentation

• https://developer.mozilla.org/en-US/docs/Web/API/SubtleCrypto/digest
• https://csrc.nist.gov/pubs/fips/180-4/upd1/final

This page describes the implementation shipped with the NOFYI Tool Factory. Review the interface output before using it in a production workflow.