Base64 String Converter
Encode plain text to Base64 and decode Base64 back to UTF-8 text instantly in your browser.
Text is converted locally in your browser. The app does not store or send your input.
Text or Base64 input
Type plain text to encode it, or paste Base64 to inspect both the encoded and decoded versions.
Live conversion results
Encoded Base64 is always shown. When the input looks like Base64, the decoded UTF-8 text appears too.
Encoded Base64
Decoded text
Results appear here as you type.
Use cases
Try Base64 String Converter for these common tasks:
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Quick API header encoding
Convert a username and password pair into Base64 for a Basic Auth header during API testing.
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Decode a value from logs
Paste a Base64 value from logs or a support ticket and read the original UTF-8 text right away.
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Encode Unicode text
Turn emoji, accented text, or CJK characters into Base64 using proper UTF-8 bytes.
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Verify encoding correctness
Compare the app's output with another implementation when debugging Base64 handling.
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Share an encoded value
Copy the encoded result for configs, documentation, tickets, or chat messages without opening a terminal.
Frequently Asked Questions
- How do I use this app?
- Enter or paste the required input, adjust any options, run the primary action, and review the result. Use the Clear/Reset control to start over.
- Is this app free to use?
- Yes. The app is free to use and does not require an account.
- What happens to my input data?
- The app MUST NOT store user-provided input. If any network request is required for a feature, the app MUST clearly disclose it in the Help section.
- Why am I getting an error or unexpected output?
- Most issues come from invalid input or incompatible options. Verify the input format, try the default settings, and use Clear/Reset before trying again.
- Where can I find instructions and troubleshooting tips?
- Use the in-app Help panel. It MUST explain inputs, options, and common mistakes, and it MUST be usable with a keyboard (including closing with Escape).
Help & instructions
Getting started
- Type or paste any text into the input field.
- The Base64-encoded result appears instantly in the output panel.
- If you paste a Base64 string, the decoded text is also shown automatically.
Features
- Live conversion as you type — no button needed.
- Auto-detects Base64 input and shows both encode and decode results.
- Full Unicode support for emoji, CJK, accented characters, and more.
Tips
- Paste a Base64 string to quickly decode it without switching modes.
- Use the Copy button to grab the output for immediate use.
- For file encoding or URL-safe mode, use the Base64 Encoder/Decoder app instead.