Encoding. Encryption. Hashing.

Three ideas people mix up. Learn the difference, then try all three yourself.

Try the Transform Lab Companion PDF

The one-line difference

Same data. Three jobs.

Encoding

Make it usable.

Reshapes data so systems can store and send it. Anyone can reverse it. No secret is involved.

Example Base64

Encryption

Keep it secret.

Scrambles data with a key so only the right key holder can read it. It protects confidentiality.

Examples AES, RSA

Hashing

Prove it is unchanged.

Turns any input into a fixed-length fingerprint. It cannot be run backwards. It protects integrity.

Examples SHA-256, SHA-3

The Transform Lab

Type anything. Watch it change.

One sentence, three transformations, live.

Your text

Encryption key

Encoding · Base64

No key needed

Encryption · keyed cipher

Needs the key

Try decrypting with key

Hashing · SHA-256

One-way

Try to reverse this hash: guess the input

Watch what happens. The Base64 decodes straight back, no secret needed. The cipher only returns your text when the key matches, and one changed letter turns it into noise. The hash cannot be reversed, and changing one character of the input gives a completely different fingerprint.

The cipher here is a simple teaching demo (a key-seeded stream cipher), not real cryptography. Nothing you type leaves your browser.

What thrillers get wrong

Four things you hear that are not true.

“I reversed the hash and got the password.”A hash has no reverse. Attackers guess inputs and compare fingerprints, which is why strong, salted, slow hashing for passwords matters.

“It is encrypted. It looks like gibberish.”Base64 looks like gibberish and is not encryption. It is encoding, and anyone can decode it in a second.

“She brute-forced the AES key in seconds.”Guessing a modern AES-256 key is out of reach. Real attacks go after weak passwords, stolen keys and flawed software instead.

“Same hash, so it is the same file. Always.”With strong hashes like SHA-256 a match is trustworthy. Older ones, MD5 and SHA-1, can be made to collide and should not be relied on.

Side by side

At a glance.

	Encoding	Encryption	Hashing
Main goal	Make data usable	Keep data secret	Verify data is unchanged
Key needed	No	Yes	No
Reversible	Yes, by anyone	Yes, with the key	No
Output size	Slightly larger than the input	Similar to the input	Fixed length
Keeps secrets	No	Yes	No, short inputs can be guessed
Typical use	Base64 in email and web addresses	HTTPS, disk and file encryption	Password storage, file integrity, signatures