Base64 Encode / Decode
Free online Base64 encoder and decoder with full UTF-8 (Chinese, emoji) support and a URL-safe mode. Runs 100% in your browser.
Runs locally · data never uploaded
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How to use
What it does
Base64 encodes arbitrary binary data into printable ASCII so it can travel safely inside JSON, HTTP or email. This tool is fully UTF-8 aware (Chinese, emoji, any multibyte text) and adds a URL-safe mode that swaps + for - and / for _ while dropping padding = — perfect for URLs and filenames.
Example
Encode 你好，世界！DevUtils:
5L2g5aW977yM5LiW55WM77yBRGV2VXRpbHM=Tick "URL-safe" and the + / characters are rewritten to - _, making the result safe to drop straight into a link.
Common uses
- Encoding credentials in JWT or Basic Auth headers
- Turning images/binary into embeddable text
- Carrying binary ids inside a URL (use the URL-safe mode)
FAQ
Q1.Is Base64 encryption?
No. It is only encoding — anyone can decode it with no key, so it offers no confidentiality. For secrecy use AES, RSA or another cipher.
Q2.Will Chinese text get mangled?
No. The tool works in UTF-8, so encoding then decoding restores Chinese, emoji and any other characters losslessly.
Q3.What is URL-safe mode for?
Standard Base64 uses `+` and `/`, which must be percent-escaped in URLs, and trailing `=` can get trimmed. The URL-safe mode replaces them and drops padding so the result sits safely in a link or filename.
Q4.Is my data uploaded?
No. Encoding and decoding happen entirely in your browser, and the tool keeps working offline.
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