tool4.dev

Security / LOCAL TOOL

Hash Generator

Generate SHA-256, SHA-384, or SHA-512 hashes locally for text or files, with optional digest verification.

Runs locally — input is never uploaded
Paste text or choose a file · max 100 MiB
Ready when you are

WHAT IT DOES

Checksums computed on your machine, not on ours.

Compute a SHA-256, SHA-384, or SHA-512 digest of pasted text or a local file up to 100 MiB, then optionally check it against an expected hexadecimal checksum. Hashing uses the Web Crypto API, the same primitive implementation the browser uses for TLS, so the hex digest matches sha256sum and every other conforming tool.

Why use it?

Use a digest to compare the bytes you received with a checksum supplied through a trusted channel. Renaming a file does not change its contents; editing even one byte can change its digest.

How to use this tool

  1. Enter the exact text to hash or choose the actual file, not just its filename.
  2. Select the same hash algorithm used by the expected checksum and generate the digest.
  3. If you have an expected digest, compare it using the verification field. A match is meaningful only to the extent that you trust the source of that expected value.

Details and limitations

  • SHA-256, SHA-384, and SHA-512 are supported; MD5 and SHA-1 are deliberately omitted as broken for integrity use.
  • Text is hashed as UTF-8 bytes, matching command-line tools operating on a UTF-8 file.
  • Files up to 100 MiB are read into memory and hashed locally, so the digest can be checked against a published checksum.
  • Output is lowercase hexadecimal, ready to compare against sha256sum output.
  • An optional expected digest is validated for the selected algorithm and reports Match or Does not match without sending either value anywhere.

WORKED EXAMPLES

A checksum with a known answer

Choose SHA-256 and hash the three characters abc, without a trailing newline. A newline changes the bytes and therefore the digest; a text hash is not a hash of a filename.

Text

abc

Expected result

ba7816bf8f01cfea414140de5dae2223b00361a396177a9cb410ff61f20015ad. A matching checksum establishes agreement with the supplied digest, not whether its publisher can be trusted.

COMMON QUESTIONS

Hash Generator questions

Does the file get uploaded to compute the hash?
No. The file is read locally through the File API and hashed with Web Crypto in your browser. No part of it is sent to tool4.dev, which is why the limit here is 100 MiB rather than something a server would have to accept.
Why are MD5 and SHA-1 not offered?
Both have practical collision attacks: MD5 collisions are trivial to produce, and SHA-1 fell to the SHAttered attack in 2017. Neither should be used for integrity verification, so this tool supports only the SHA-2 family.
Will this match sha256sum on my machine?
Yes, for the same bytes. Hashing a file produces an identical digest. Hashing text hashes its UTF-8 encoding, with no trailing newline, which is where results sometimes differ from a shell pipeline.
How do I verify a published checksum?
Choose the matching SHA algorithm, hash the text or file, and paste the expected lowercase or uppercase hexadecimal digest into the optional field. The result reports whether the two digests match and rejects the wrong length or non-hex input.