Is Base64 encoding secure?

No. Base64 is encoding, not encryption — anyone can decode it instantly. Use it for safe transport of binary data, not to hide sensitive information.

Does MyToolsBag store my text or images?

No. Base64 encoding and decoding runs entirely in your browser. Your data never leaves your device.

Can I encode images to Base64?

Yes. Drop or upload any image and MyToolsBag returns a Base64 data URL you can paste directly into HTML or CSS.

What is Base64 used for?

The main use cases are embedding small images as data URLs in CSS or HTML, sending binary data inside JSON, signing JWT tokens, HTTP Basic Auth headers, and legacy email attachments. It's a transport encoding — a safe way to squeeze bytes through systems that expect ASCII text.

Why is my Base64 output about 33% larger than the input?

That's expected. Every 3 bytes of input become 4 bytes of Base64 output, so the encoded string is always roughly 4/3 the size. This is why Base64 is fine for tiny icons but a bad choice for large files — use a proper multipart upload instead.

What's the difference between Base64 and Base64URL?

Plain Base64 uses + and / characters, which need to be escaped in URLs. Base64URL replaces them with - and _ and drops the trailing = padding. JWTs, OAuth tokens, and anything that lives in a query string use Base64URL. If a decoder rejects a token with "invalid character", you're likely feeding Base64URL into a plain-Base64 decoder.

How do I decode Base64 in JavaScript, Python, or Bash?

JavaScript: atob(encoded) for text, or Buffer.from(str, 'base64') in Node. Python: base64.b64decode(encoded). Bash: echo 'SGVsbG8=' | base64 -d. All three produce the same output for the same input.

What does the '=' at the end of a Base64 string mean?

It's padding. Base64 output length is always a multiple of 4, so if the input isn't a multiple of 3 bytes, the encoder adds one or two = characters to fill it out. Base64URL usually strips them; strict Base64 keeps them.

MyToolsBag

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Base64 Encoder & Decoder

Encode text or images to Base64, or decode Base64 strings back to text. Runs entirely in your browser — nothing is uploaded.

Input

0 chars

Output

0 chars

Common use cases

Where Base64 shows up in everyday development work.

Email attachments

MIME encodes binary attachments in Base64 so any mail server can relay them as plain text.

Inline images

Embed small icons or logos directly in HTML or CSS via data: URIs to skip an extra HTTP request.

API tokens & auth

Basic auth headers and JWT segments encode credentials and payloads as URL-safe Base64.

Data URIs in CSS

Background images, fonts, and SVG sprites can be inlined as Base64 to ship as a single asset.