Base64 Encoder & Decoder
Free online Base64 encoder and decoder with full UTF-8 support. Convert text to Base64 or decode Base64 back to plain text instantly. Everything runs in your browser — no data is uploaded.
How to use
- Type or paste your text into the input box on the left.
- Click "Encode →" to convert text to Base64, or paste Base64 and click "← Decode".
- Copy the result with one click, or use "Swap" to feed the output back in and chain conversions.
What is Base64 Encoder & Decoder?
Base64 is a binary-to-text encoding scheme that represents binary data using only 64 ASCII characters (A–Z, a–z, 0–9, + and /). It is widely used to embed images in HTML or CSS, carry binary data inside JSON or XML, and encode payloads in data URIs, email attachments and JWT tokens.
This tool converts any text — including Chinese and other multi-byte Unicode characters — to Base64 and back. The encoding follows the UTF-8 standard, so the output is compatible with every major platform and programming language. Note that Base64 is an encoding, not encryption: it provides no security and anyone can decode the result.
Frequently asked questions
Is my data uploaded to a server?
No. Encoding and decoding run entirely in your browser with JavaScript. Nothing is sent anywhere, so it is safe to use with sensitive text.
Does it support Chinese characters or emoji?
Yes. Text is first encoded as UTF-8 bytes and then converted to Base64, so Chinese characters, emoji and any other Unicode text round-trip correctly.
Why is the Base64 output longer than the input?
Base64 represents every 3 bytes with 4 characters, so the output is about 33% larger than the original data. This is normal, not a bug.
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