About this base64 encoder / decoder
Convert ordinary text into standard Base64, or decode Base64 back into readable UTF-8 text. Switch modes before running the transformation. This is useful when inspecting a text payload or preparing a value for a system that expects Base64. Unicode text is encoded as UTF-8 bytes first. Processing happens locally and the output can be copied directly without sending its contents to an external service.
How the base64 encoder / decoder works
Encoding converts UTF-8 bytes to the standard Base64 alphabet. Decoding validates padded Base64 and then decodes bytes as UTF-8.
Base64 Encoder / Decoder examples
Hello
SGVsbG8=
✓
4pyT
Limitations & privacy
Text only; arbitrary binary files are not supported. Use standard padded Base64, not Base64URL. Maximum input: 100,000 characters. Base64 is encoding, not encryption.
Inputs and results stay in this browser. Only tool identifiers are stored for your recently used tools. You can clear that history from the directory.
Base64 Encoder / Decoder: frequently asked questions
Is Base64 private encryption?
No. Anyone with the string can decode it.
Are emoji supported?
Yes, through UTF-8 encoding.
Why did decoding fail?
The input may be unpadded, use the URL-safe alphabet, or contain bytes that are not valid UTF-8.
Updated September 20, 2026