The detailed guide below is currently available in English.
What a SHA-256 hash is good for
SHA-256 squeezes any input — a password, a file, a whole novel — into a fixed 256-bit fingerprint. Change one character anywhere and roughly half the output bits flip, which makes the digest a rigorous equality check: publish the hash of a download so readers can verify it, compare a freshly typed configuration against a known-good digest, or deduplicate content without storing it. Identical input always yields the identical digest, and no practical method is known for finding two inputs that share one.
Hashing is not encryption
The two get confused constantly, and the difference matters. Encryption is reversible by design: with the key you get the original back. A hash is one-way — the digest is not a scrambled copy of your text but a short summary from which the text cannot be recovered. That is exactly why passwords should be hashed, not encrypted, on a server; and it is also why a hashed password cannot be "unhashed" by this or any tool. For passwords in the real world, use a slow, memory-hard scheme such as Argon2 or bcrypt rather than raw SHA-256.
Repères pour la France
Repères locaux pour la France, utiles dans les calculs du quotidien :
- TVA: 20 % en taux normal (5,5 % alimentaire, 10 % restauration) ; les prix sont TTC par loi.
- Monnaie & paiements: Euro (€) ; paiement sans contact et carte bancaire très répandus, virement SEPA instantané en développement.
- Unités & nombres: Système métrique ; virgule décimale et espace pour les milliers : 1 234,56 €.
- Santé: Carte Vitale ; l'Assurance Maladie rembourse en base ≈ 70 % des soins, le reste par mutuelle.
- Pourboire: Service compris : aucun pourboire obligatoire ; arrondir suffit.
Mis à jour : octobre 2026 · valeurs 2025, sources officielles ci-dessus.
Questions fréquentes
Does my text get sent to a server?
No. The SHA-256 implementation runs in JavaScript on this page, so hashing happens on your device. The text you type never leaves the browser, which makes the tool safe for secrets you only need to fingerprint.
Why only SHA-256?
SHA-256 is the modern default: fast, widely supported, and unbroken. Older functions such as MD5 and SHA-1 are kept around only for legacy compatibility because collisions have been demonstrated against both, so this tool skips them.
Can two different texts have the same hash?
Mathematically yes — 256 bits cannot name every possible input uniquely — but no collision has ever been found for SHA-256, and finding one by brute force would take more energy than burning all the world’s fossil fuel. For any practical purpose, equal digests mean equal inputs.