Base64 Encoder/Decoder
Encode and decode UTF-8 text as Base64 in your browser
Accepted upload: .txt · max 5 MB. Encoding uses UTF-8 so Unicode and emoji are preserved.
Input
Plain text or Base64
Output
Encode or decode result
Frequently asked questions
Common questions about the Base64 Encoder/Decoder.
How does Base64 Encoder/Decoder work?
Paste or upload text, then Encode or Decode. Encoding turns UTF-8 text into Base64. Decoding accepts standard Base64 and URL-safe Base64 (- and _) with padding fixed when needed.
Does my text leave my device?
No. Encoding and decoding run in your browser. ToolsArk does not upload your input to a server.
Can I decode binary Base64?
This tool expects the decoded bytes to be valid UTF-8 text. Binary payloads that are not UTF-8 text will fail. Use a dedicated binary/file tool if you need raw bytes.
What are the size limits?
Text input is capped around 1.5 million characters. File uploads accept .txt up to 5 MB.
What does the detection badge mean?
It is a heuristic hint (plain text, looks like Base64, or invalid Base64). Always use Encode or Decode explicitly — the badge does not change your text by itself.
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