Base64 Encoder & Decoder
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Encode any text to Base64 and decode Base64 back to plain text. Full Unicode support, runs entirely in your browser.
Base64 Encoder & Decoder
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About This Tool
What is Base64?
Base64 is a binary-to-text encoding scheme that represents binary data using only 64 ASCII characters (A–Z, a–z, 0–9, +, /). It's used to transmit binary data through systems that only handle text safely — for example, email attachments, JSON payloads, and data URLs in CSS or HTML.Common Uses
- Email attachments (MIME): binary files are Base64-encoded inside text emails
- Data URLs: embed images directly in HTML/CSS as
data:image/png;base64,... - HTTP Basic Auth: "user:password" is sent Base64-encoded in headers
- JWT tokens: the header and payload are Base64URL-encoded JSON
Important Note
Base64 is not encryption. Anyone can decode it instantly. Don't use Base64 for sensitive data — use proper encryption like AES.Frequently Asked Questions
Does Base64 work with Unicode and emoji?
Yes. This tool handles full Unicode by encoding to UTF-8 first, then to Base64. So 'café 🎉' encodes and decodes correctly without corruption.
Why does Base64 make data ~33% bigger?
Base64 uses 6 bits per character (since 2^6 = 64), but each character takes 8 bits to transmit. So every 3 bytes of binary become 4 ASCII characters — a 33% size increase. That's the cost of safe text-only transmission.
Is there a URL-safe variant?
Yes — Base64URL replaces '+' and '/' with '-' and '_' so the result can appear in URLs without escaping. JWT tokens use Base64URL. This tool produces standard Base64; convert to URL-safe with a simple find-replace.