Why do I get an error decoding my text?

This usually means the input isn't valid Base64 — check for typos, missing characters or extra whitespace.

Does this decode URL-safe Base64 too?

Yes — the decoder automatically converts URL-safe characters back before decoding.

Can I decode a JWT with this tool?

You can decode a JWT's header or payload segment individually, but this tool does not verify a JWT's signature.

Is my text uploaded anywhere?

No — decoding happens entirely in your browser.

Does this handle missing padding automatically?

Yes — the decoder adds any missing = padding characters automatically before decoding.

What happens if I paste non-Base64 text?

You'll see a clear error message telling you the input isn't valid Base64, rather than garbled output.

Outils d'Encodage

Décodeur Base64 — Outil en Ligne Gratuit

Décodez du texte encodé en Base64 en contenu lisible.

Utiliser Cet Outil

Fonctionne dans Votre Navigateur
Résultats Instantanés
100% Privé

Your Text

What Is Base64 Decoding?

Base64 decoding reverses Base64 encoding, converting a string of A-Z, a-z, 0-9, + and / (or their URL-safe equivalents) back into its original text. It is the tool to reach for whenever you have a Base64 string — from a JWT token, an API response, or an email header — and need to read what it actually contains.

This decoder automatically handles both standard and URL-safe Base64 input, so you don't need to know in advance which variant you're working with.

Qui Utilise Cet Outil ?

Pour les Entreprises

Decode a Base64-encoded value returned by an API response.

Pour un Usage Personnel

Decode a Base64 message to read its original content.

Pour les Étudiants

Explore how Base64 decoding works for a networking or web development course.

Pour les Bureaux

Decode a configuration value stored in Base64 format.

Pourquoi Utiliser Cet Outil

Fonctionnalités Clés

Handles Both Variants

Automatically decodes both standard and URL-safe Base64.

Instant Decoding

Output updates immediately as you paste in a Base64 string.

100% Private

Your text is never uploaded or stored.

One-Click Copy

Copy the decoded result straight to your clipboard.

Le Résultat

Avantages

Read Encoded Values Instantly

See the real content behind a Base64 string in one click.

No Manual Padding Fixes

The tool automatically fixes missing padding characters.

No Software Needed

Decode directly in the browser — no command line required.

Étape par Étape

Comment Utiliser Décodeur Base64

Paste the Base64 String

Add the Base64-encoded text you want to decode.

Read the Decoded Result

The original text appears automatically.

Copy the Result

Use the Copy button to grab the decoded text.

Spécifications

Détails Techniques

Détail	Valeur
Entrée	Standard or URL-safe Base64 text
Traitement	No practical limit — handled entirely by your browser
Sortie	Exact decoding back to the original UTF-8 text

Vous Pouvez le Vérifier

Confidentialité & Sécurité

Ce qui se passe réellement avec votre fichier lorsque vous utilisez cet outil.

100% Client-Side

This tool runs entirely inside your browser using JavaScript — nothing you type or generate is ever sent anywhere.

No Upload, Ever

There is no file upload and no server processing step — your data never leaves your device.

Works Offline

Once this page has loaded, the tool keeps working even without an internet connection.

Nothing Stored

Nothing you enter is saved on our servers — refreshing the page clears everything.

No Tracking of Your Input

We have no way to see what you type, generate or convert with this tool.

Obtenir de Meilleurs Résultats

Astuces

Remove Extra Whitespace First

If decoding fails, check for accidental line breaks or spaces copied along with the Base64 string.

Use This to Inspect JWT Payloads

JWT tokens are made of Base64-encoded segments — decode the middle segment to see the payload (note: this does not verify the signature).

Questions Fréquentes