SHA-256 Generator

SHA-256 for a string or a whole file.

FREE - NO SIGN-UP - RUNS ON YOUR DEVICE

Hashed in this tab, not uploaded

  • SHA-256and three more
  • crypto.subtledoes the work
  • 0uploads
  • 1 tapto copy
Specification

SHA-256 Generator at a glance

Input
Text or one file, plus a choice
Output
A SHA-256 hex digest
Method
crypto.subtle, built into browser
Comparing digests
Any difference means other bytes
What it is not
A fingerprint, not encryption
Price
Free
Account needed
None
Where processing happens
On your device
How to

How to use SHA-256 Generator

  1. 1

    Add the text or file

    Paste a string or choose a file.

  2. 2

    Select SHA-256

    Pick SHA-256 from the list.

  3. 3

    Read and compare

    Copy it, or compare with the published one.

Questions

Frequently asked questions

How do I check a download with SHA-256?

Choose the downloaded file here, read the digest, and compare it with the one the publisher printed. If a single character differs, the file is not the one that was published.

Is SHA-256 encryption?

No. It is one way. A digest is a fixed-length fingerprint of the bytes and there is no key that brings the original back.

Which should I use, SHA-256 or MD5?

SHA-256, unless a publisher gave you an MD5 to match. MD5 collisions can be made on purpose, so it only tells you a file arrived intact.

Does a large file get sent somewhere to be hashed?

No. The file is read inside this browser tab and hashed there. Nothing is uploaded, and the digest is not stored or logged.

Background

Reading a digest

Paste a string or choose a file, and the digest is worked out by the browser's own crypto.subtle. SHA-1, SHA-512 and MD5 are one switch away.

  • A digest is fixed length whatever goes in, so a one-line string and a large file produce results the same size.
  • Digests are compared whole. Checking the first and last few characters is a habit worth breaking.
  • A published digest only helps if it came from somewhere you trust, not from the same page as the download.
  • SHA-512 is on the same list; it is longer rather than stronger for most purposes.

Full specification

Specification of the SHA-256 Generator tool
InputPasted text, or a single file taken from this device, together with your choice of algorithm.
OutputA SHA-256 hexadecimal digest. SHA-1, SHA-512 and MD5 digests come from the same input.
Methodcrypto.subtle, the hashing built into the browser. MD5 is separate local JavaScript, kept for checksums.
Comparing digestsSet the published digest beside the one shown and read them character by character; any difference means different bytes.
What it is notNot encryption. A digest cannot be turned back into the input, and it hides nothing about a file you already hold.
PriceFree. Supported by clearly labelled ads outside the working area.
Account neededNo.
Where processing happensIn your browser tab. Your input is never uploaded.
Next step

Keep going with the same files

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