Free Base64 Encoder Decoder Online

What Is a Base64 Encoder Decoder?

Base64 is a way of representing binary data using only 64 safe text characters: the letters A to Z and a to z, the digits 0 to 9, plus and slash. It was designed so that data such as images, files and special characters can travel through systems that only handle plain text, like email, JSON and URLs. A Base64 Encoder Decoder converts in both directions.

When you encode, this tool first turns your text into UTF-8 bytes, so emoji, accented letters and non-Latin scripts work correctly, and then maps those bytes to Base64. Decoding reverses the process and checks the input for mistakes. The URL-safe option swaps plus and slash for hyphen and underscore and drops the equals padding, which is the variant used in tokens and web addresses.

Base64 is an encoding, not encryption. Anyone can decode it, so it should never be used to protect secrets.

How to Use the Base64 Encoder Decoder

1. Choose Encode to turn text into Base64, or Decode to turn Base64 back into text.
2. Type or paste your content into the input box. The output updates as you type.
3. Tick URL-safe Base64 if the result will be used inside a URL, filename or token.
4. Press Swap input and output to feed the result back in, which is useful for checking a round trip.
5. Copy the output or download it as a text file.
6. To encode a file, pick it in the file section and copy the Base64 string that appears.

Key Features of Our Base64 Encoder Decoder

• Encode and decode with full UTF-8 and emoji support
• URL-safe Base64 option without padding
• Accepts Base64 with line breaks, spaces and missing padding
• Clear messages for invalid or binary Base64
• File to Base64 conversion up to 5 MB
• Swap button for quick round-trip checks
• Copy and download buttons
• Runs locally in your browser with no uploads

Benefits of Using an Online Base64 Encoder Decoder

Developers meet Base64 constantly: in data URLs, API authentication headers, JSON Web Tokens, email attachments and configuration files. Having a dependable Base64 Encoder Decoder in the browser avoids writing throwaway scripts just to read one value.

Because the conversion is local, you can safely inspect sample tokens and payloads without sending them to a third-party server. The error messages also save time by telling you whether a string is simply malformed or valid binary data.

Your privacy comes first. The Base64 Encoder Decoder runs entirely in your web browser. Nothing you enter is sent to our servers, which keeps your data private and makes results appear instantly. See our Privacy Policy for details.

Common Use Cases for the Base64 Encoder Decoder

• Decoding the payload section of a JSON Web Token
• Creating Basic Authentication header values for testing
• Embedding small files or images in HTML, CSS or JSON
• Reading Base64 strings found in logs and configuration files
• Preparing text for systems that only accept ASCII
• Checking data URLs and email attachment encodings
• Teaching how binary-to-text encoding works
• Converting small files to Base64 for API requests

Tips for Getting the Best Results

• Base64 makes data about one third larger, so avoid it for big files when a direct upload is possible.
• If decoding fails, check for stray characters such as quotes, a data URL prefix or missing characters at the end.
• Use the URL-safe option when the output goes into a URL, cookie or filename.
• Remember that Base64 is not encryption. Do not use it to hide passwords or personal data.
• When decoding a JWT, decode each dot-separated section on its own.
• If the result looks like gibberish, the original data is probably binary rather than text.

Base64 Encoder Decoder FAQ

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