What is Base64?

Base64 is a binary-to-text encoding. It converts bytes (binary data) into a limited set of readable ASCII characters:

• A-Z, a-z, 0-9, +, / (and = padding)

Because the output is plain text, Base64 is often used in places where you can only safely transmit text, for example:

• JSON / XML payloads
• URLs (usually with Base64URL variant)
• Email (MIME)
• Embedding small files in text formats

What this tool does

On the Base64 page (/en/base64) you can:

• Encode text into Base64
• Decode Base64 back into text
• Quickly verify whether a string looks like Base64

How to use (examples)

Encode a string

Input:

hello world

Output (Base64):

aGVsbG8gd29ybGQ=

Decode a Base64 string

Input:

aGVsbG8gd29ybGQ=

Output:

hello world

Common pitfalls

1) Base64 is not encryption

Base64 does not protect your data. It only changes representation.

If you need confidentiality, use real encryption (e.g. AES-GCM) and keep keys secure.

2) Padding and newlines

• Many Base64 strings end with = or ==.
• Some systems insert line breaks every 76 characters (email/MIME). You may need to remove whitespace before decoding.

3) Base64 vs Base64URL

When you put Base64 into URLs, + and / may be problematic.

Base64URL typically:

• Replaces + with -
• Replaces / with _
• Removes = padding

If you see those characters, the input may be Base64URL rather than standard Base64.

Privacy & security

• This tool is designed to run client-side (in your browser).
• Your input should not be uploaded.

Even so:

• Avoid pasting passwords, private keys, or personal data on public/shared computers.
• If the data is highly sensitive, prefer offline tools.

FAQ

Why does my decoded text look like gibberish?

That usually means the Base64 content represents binary data, not UTF-8 text (for example, an image file or compressed bytes). In that case you may need to save the decoded bytes as a file instead of displaying as text.

How can I link from this doc to the tool page?

Use normal Markdown links, for example:

• Open the Base64 tool