WebTool

Base64 Encoder / Decoder

Free online Base64 encoder and decoder built on UTF-8 bytes — non-Latin text and emoji round-trip cleanly, all local.

Privacy: all processing happens locally in your browser. Your input never leaves your device.

What is Base64 Encoder / Decoder?

Base64 encodes arbitrary bytes into 64 printable ASCII characters and is widely used to carry binary data over text protocols — inline images, Basic authentication, JWT payloads and more. The browser's native btoa cannot handle non-Latin text; this tool encodes and decodes on a UTF-8 byte stream, so Chinese characters and emoji round-trip correctly, and invalid Base64 input is detected and reported. All processing is local.

How to Use

  1. Paste plain text or Base64 text
  2. Choose encode or decode
  3. Copy the result

FAQ

Why does Base64-decoded text turn into garbled characters?
The native atob/btoa treats input byte by byte as Latin-1 without UTF-8 handling. This tool processes the byte stream through TextEncoder/TextDecoder, so multi-byte text never gets garbled.
Is Base64 encryption?
No. Base64 is only an encoding — anyone can decode it. Never use it to protect sensitive information.
How is Base64URL different?
Base64URL replaces + and / with - and _ and drops the trailing =, avoiding reserved-character conflicts in URLs and JWTs.

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Last updated 2026-09-04