Base64 Encode / Decode
Encode text to Base64 and decode Base64 strings online. Full Unicode/UTF-8 support. Free, fast, client-side Base64 converter tool.
Why Use the Base64 Encoder/Decoder?
Base64 encoding is used everywhere in web development — from data URLs and email attachments to JWT tokens and API payloads. Our tool provides a quick way to encode and decode Base64 with full Unicode support, ensuring international text is handled correctly.
Key Features
- Two-tab interface: separate Encode and Decode modes
- Full Unicode/UTF-8 support for international characters
- Swap button to instantly switch encoded and decoded content
- One-click paste from clipboard and copy to clipboard
How to Use
- Select the Encode or Decode tab
- Paste your text or Base64 string in the input area
- Click the action button and copy the result
Technical Details
Encoding uses btoa() with a Unicode-safe approach: text is first encoded as UTF-8 bytes via encodeURIComponent/unescape, then converted to Base64. Decoding reverses this process using atob() and decodeURIComponent/escape. This ensures all Unicode characters are correctly handled, not just ASCII.
FAQ
Does this support non-English characters?
Yes, our tool uses UTF-8 encoding before Base64 conversion, so all Unicode characters including Chinese, Arabic, and emoji are supported.
What's the difference between encodeURI and Base64?
Base64 converts any binary data to ASCII text using 64 characters (A-Z, a-z, 0-9, +, /). URL encoding converts special characters to %XX format. They serve different purposes.
Related articles
Base64 in Plain Words: What It Is and What It's For
What a string like SGVsbG8sIHdvcmxkIQ== means, why Base64 is not encryption, and where it appears: email, JWT, data URIs. Encode and decode online in seconds.
JWT tokens: what's hiding behind “eyJhbGciOi…” and how to read it
What a JWT is made of, why tokens start with “eyJ”, how a signature differs from encryption, where to check expiry, and why secrets don't belong in the payload.
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