Why do standard atob/btoa functions fail with emojis?

JavaScript's native btoa() handles only Latin1 characters. DevTools uses modern TextEncoder and UTF-8 byte buffers to safely handle all UTF-8 characters and emojis.

Base64 Encoder & Decoder

Core

Encode and decode text, hex, URL-safe Base64, and convert images/files to Data URIs.

URL-Safe (RFC 4648)

Plain Text (UTF-8)

UTF-8 Source

UTF-8•100% Local Sandbox

1 line • 115 Bytes • 94 chars

Base64 Encoded Result

Standard Base64

UTF-8•100% Local Sandbox

1 line • 0 Bytes • 0 chars

About Base64 Encoder & Decoder

Base64 is a binary-to-text encoding scheme that represents binary data in an ASCII string format using a radix-64 representation. It is widely used in email (MIME), data URLs, basic HTTP authentication headers, and web tokens to safely transmit data across text-only protocols.

Zero-Upload Privacy Guarantee

Base64 is frequently used to encode authorization tokens, private keys, API secrets, and sensitive credentials. Browser-based encoding ensures secrets are never transmitted across the network.

Client-Side Sandbox● 100% Air-Gapped

Key Capabilities & Features

Full UTF-8 unicode support (handles emojis, foreign scripts, and special symbols safely)

URL-safe Base64 toggle (RFC 4648 §5 compliant)

File & Image to Base64 Data URI converter with live visual image preview

Base64 to downloadable file decoder

Character count, input/output size comparison, and overhead percentage

How to use this Base64 encode online

Select Input Mode

Choose 'Text Mode' for strings or 'File / Image Mode' to upload a local asset.

Toggle Encode or Decode

Select whether you want to encode plain data into Base64 or decode Base64 back to readable text.

Configure URL-Safe option

Enable 'URL-Safe' to swap '+' with '-' and '/' with '_', and strip padding '=' characters.

Copy or Download

Copy the result or use the HTML <img> embed tag snippet for images.

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Frequently Asked Questions

No. Base64 is an encoding scheme, not encryption. Anyone can decode a Base64 string instantly without a key. Never use Base64 alone to protect confidential passwords or secrets.