Base64 Encoder & Decoder

Encode text to Base64 or decode Base64 back to plain text instantly, with full Unicode support. Everything runs locally in your browser.

The Base64 Encoder & Decoder converts plain text into Base64 and back again instantly in your browser, with full Unicode support so accented characters, emoji and non-Latin scripts round-trip correctly. Developers use Base64 constantly to embed binary-safe data inside text formats such as JSON, URLs, email attachments and data URIs, and this tool handles both directions of that conversion without needing a code snippet or terminal command.

Encoding and decoding both happen locally as you type, so there is no delay waiting for a server round trip and no risk of pasting sensitive tokens or credentials into a third-party service. Paste a Base64 string to decode it back to readable text, or type plain text to see its encoded form immediately, with the output ready to copy straight into your code, config file or message.

How to use the Base64 Encoder & Decoder

1. Choose whether you want to encode text to Base64 or decode Base64 back to text.
2. Paste or type your input into the text box.
3. Watch the converted output appear instantly in the result box.
4. Copy the result using the copy button.
5. Switch modes at any time to reverse the conversion on a new input.

Why use this tool

Full Unicode support

Text containing accented letters, emoji or non-Latin scripts encodes and decodes correctly, unlike some naive Base64 implementations that only handle plain ASCII.

Instant two-way conversion

Both encoding and decoding update live as you type or paste, with no submit button or waiting for a server response.

Safe for sensitive strings

Because conversion happens locally, API keys, tokens or credentials being decoded for debugging are never transmitted anywhere.

Copy-ready output

The result box is formatted for a single click copy straight into code, a config file or a browser address bar.

Common use cases

• Decoding a JWT token payload segment to inspect its claims during debugging.
• Encoding a small image or file into a Base64 data URI for embedding in CSS or HTML.
• Decoding a Base64-encoded email attachment header to check its content.
• Encoding a string for use inside a URL query parameter that requires binary-safe text.
• Checking what a suspicious Base64-looking string in a log file actually says.

Base64 is not encryption

Base64 is reversible encoding, not encryption — it exists purely to represent binary data safely inside text-based systems, and anyone can decode it instantly with any Base64 tool. Never rely on Base64 to protect passwords, tokens or other secrets.

Why the output is longer than the input

Base64 encodes every three bytes of input as four ASCII characters, which inflates the size by roughly 33%. This overhead is the trade-off for making arbitrary binary data safe to place inside text formats like JSON or XML.

Common uses in development

Base64 commonly appears in JWT tokens, data URIs for inline images, email MIME attachments, and Basic HTTP authentication headers. Recognising the characteristic mix of letters, digits, plus, slash and trailing equals signs is a good sign a string is Base64 encoded.

Decoding errors and troubleshooting

If decoding fails, check that the input has no line breaks or stray whitespace inside it and that padding characters at the end have not been trimmed off, since both can produce invalid or garbled output.

Frequently asked questions

Is Base64 a form of encryption?

No. It is reversible encoding designed to carry binary data safely through text channels — anyone can decode it, so never use it to protect secrets.

Why is Base64 output longer than the input?

Every three bytes become four ASCII characters, which adds about 33% to the size. That overhead is the cost of being safe to transmit as plain text.

Is Base64 Encoder & Decoder free to use?

Yes. Base64 Encoder & Decoder on Klipza is completely free with no account, no subscription and no watermark on your files, and there is no daily usage limit.

Are my files safe when using Base64 Encoder & Decoder?

Processing happens locally in your browser wherever technically possible, so your files are not uploaded to a server, stored or shared with third parties.

Does Base64 Encoder & Decoder work on mobile phones?

Yes. It is fully responsive and runs in any modern browser on Android, iPhone, iPad, Windows and macOS — nothing to install.