Unicode configuration value
Encoding a value containing 東京 and an emoji works because the text becomes UTF-8 bytes before Base64 conversion. Decoding restores the original characters.
Base64 Encoder and Decoder
Encode UTF-8 text to standard Base64 or decode Base64 back to Unicode text locally in your browser, with strict malformed and non-text error handling.
Maintained by Roshan.
Browser-local encoder
Use Base64 Encoder and Decoder
This text tool uses UTF-8 before Base64 encoding and rejects decoded binary that is not valid UTF-8.
During the latest release check, a known Base64 sample was decoded in the browser and matched the expected text. The reverse action then encoded that text back to the original Base64 value without a network request.
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Browse all developer and data toolsAbout Base64 Encoder and Decoder
Base64 turns bytes into printable ASCII characters so data can travel through text-oriented systems. It is encoding, not encryption: anyone can reverse it, and the output is usually about one-third larger than the original bytes. This tool handles text deliberately. Encoding first converts Unicode text to UTF-8 bytes, so names, emoji, and non-Latin scripts round-trip correctly. Decoding validates standard Base64, reconstructs the bytes, and then requires those bytes to be valid UTF-8 text. Binary files are rejected instead of being displayed as damaged characters. Both directions run locally without posting tokens, credentials, or payloads to a decoding service.
Using Base64 Encoder and Decoder
- Choose Encode when the input is ordinary text. The browser's UTF-8 encoder converts each character sequence into bytes, including multibyte characters. Those bytes are then mapped into the standard A-Z, a-z, 0-9, plus, and slash Base64 alphabet with equals padding when required.
- Choose Decode for standard Base64. Whitespace is ignored because encoded data is often line-wrapped in email or configuration files. Other unexpected characters, invalid padding shape, and impossible lengths are rejected before decoding.
- Decoded bytes pass through a strict UTF-8 decoder. A valid Base64 string can represent an image, compressed archive, or arbitrary binary sequence; that does not make it readable text. The tool reports this distinction rather than substituting replacement symbols.
- The result reports input bytes and output character counts. Base64 works in groups of three input bytes and four output characters, so expansion is expected. Copy transfers only the displayed result to the local clipboard.
- Input is limited to one million characters. This page is intended for text snippets, API payload fragments, basic credentials during local debugging, and configuration values. Large files need a streaming file encoder with download controls.
Where base64 encoder and decoder helps
Binary image data
A PNG may be valid Base64 but is not UTF-8 text. This text-focused tool stops with a clear binary-data message rather than showing corrupted output.
Before you use the result
- Base64 provides no secrecy or authenticity. Encoding a password, API key, or personal record does not protect it. Use encryption and appropriate key management when confidentiality matters, and avoid placing credentials in URLs or public logs.
- This page uses standard Base64, not the Base64URL alphabet used by JWT segments. Base64URL replaces plus and slash with hyphen and underscore and often removes padding. The JWT decoder already handles that separate format.
- A successful decode means the syntax and UTF-8 text are valid; it does not establish who created the content or whether it is safe to execute. Treat decoded HTML, commands, and scripts as untrusted input.
Questions about Base64 Encoder and Decoder
Is Base64 encryption?
No. It is a reversible representation of bytes and offers no password, key, secrecy, or tamper protection.
Does it support emoji and international text?
Yes. Encoding uses UTF-8 and decoding requires valid UTF-8, so multilingual text and emoji round-trip correctly.
Why is my valid Base64 rejected as non-text?
The decoded bytes likely represent a file or another binary format. This tool intentionally returns only valid UTF-8 text.
Is the input sent anywhere?
No. Byte conversion, Base64 processing, validation, and copying occur inside the browser with no tool endpoint.
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