About Decode Base64
Use the Base64 decoder online to read text that was encoded as UTF-8 bytes. It can decode URL safe Base64 text by accepting - and _ alongside the standard alphabet. Whitespace is ignored, but the decoded bytes must still form valid UTF-8.
How to decode Base64 into readable text
- Paste a Base64 payload, without a data-URL prefix.
- Select Process to decode and validate the UTF-8 bytes.
- Review the text and copy or download decoded.txt.
A practical example
- Input
SGVsbG8=
- Result
Hello
A valid Base64 representation of a binary file is not necessarily valid UTF-8 text.
Supported input and limitations
- This is a text decoder, not an image, PDF, or arbitrary binary-file decoder. Invalid UTF-8 produces an error.
- It does not decompress a payload, decrypt ciphertext, validate a JWT signature, or remove a data: URL prefix automatically.
Processing happens on your device. Read about local processing and optional workspace recovery.
Frequently asked questions
Why does valid Base64 fail to decode as text?
The underlying bytes may be binary data, compressed content, or a different character encoding. This tool deliberately requires valid UTF-8.
Can I decode Base64URL strings?
The URL-safe - and _ characters are normalized before decoding. The decoded content must still be UTF-8 text, and this operation does not verify authenticity.