Base64 String Encoder/Decoder
Encode plain text to Base64 or decode a Base64 string back to text, with full Unicode support.
Recommended Settings
Pro Tips
- •Base64 encoding uses proper UTF-8 byte handling, so emoji and non-Latin characters round-trip correctly, not just plain ASCII text
- •Use the swap button to instantly feed the current output back in as input and flip direction, handy for verifying a round-trip
- •Base64 makes text roughly 33% larger, since it represents every 3 bytes of input as 4 printable characters
- •This is standard Base64 with padding, compatible with most systems - for URL-safe Base64, replace + with - and / with _
Most Popular
Most developers use this to decode a Base64-encoded JWT payload segment or API token to inspect its contents
When to Use This Tool
Encode text containing special characters safely for inclusion in a JSON field or URL.
Decode a Base64-encoded HTTP header or token segment to read its contents.
Quickly check what a chunk of Base64 text actually decodes to during debugging.
Encode a username:password pair for use in an HTTP Basic Authentication header.
How It Works
Convert your text to UTF-8 bytes, or your Base64 string back to raw bytes
Apply the browser's built-in Base64 encoding or decoding algorithm to those bytes
Convert the result back to a readable string using UTF-8 decoding
100% Private
Files never leave your device. All processing happens locally in your browser.
Lightning Fast
Powered by Client-side UTF-8 and Base64 encoding for optimal performance on modern browsers.
Open Source
Built with verified, open-source libraries. Fully transparent.
Frequently Asked Questions
Does this support Unicode characters like emoji?
Yes, text is converted to UTF-8 bytes before Base64 encoding, so emoji, accented letters, and non-Latin scripts all encode and decode correctly.
Why did decoding fail?
The input isn't valid Base64 - check for missing padding characters, stray whitespace, or characters outside the standard Base64 alphabet (A-Z, a-z, 0-9, +, /).
Is this the same as encryption?
No. Base64 is just a reversible encoding for representing binary data as text - it provides no security or confidentiality, since anyone can decode it instantly.
Is my text sent to a server?
No. All encoding and decoding happens locally in your browser.