Encode & convert

Base64 and Base64URL encoder / decoder for UTF-8

Encode and decode UTF-8 text with Base64 or Base64URL. Check alphabet, padding and invalid UTF-8 with examples and troubleshooting tips.

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How to use

Supports Unicode and Base64URL. Decoding validates the encoding and UTF-8 instead of silently replacing corrupt data.

Your input stays yours

Step by step

Choose Base64 or Base64URL to match the source.
Enter plain text and choose Encode, or encoded text and choose Decode.
Copy the result; paste it back and use the reverse operation for a round-trip check.

UTF-8 example

Hello, 世界

Standard Base64 should be SGVsbG8sIOS4lueVjA==. Decoding it should restore the same Chinese characters and space.

Frequently asked questions

Is Base64 encryption?

No. It is reversible encoding and can be decoded without a key. It does not protect passwords or secrets.

How does Base64URL differ?

Base64URL uses - and _ instead of + and /. This tool omits trailing = in Base64URL output and validates length, alphabet and padding during decoding.

Why can images or compressed data fail to decode?

Output is UTF-8 text, not arbitrary binary files. Valid Base64 may decode to bytes that are not valid UTF-8, causing an error without implying the original file is corrupt.