Free Online Base64 Encoder & Decoder
Encode any text string to Base64 or decode a Base64 string back to plain text — instantly in your browser. No uploads, no account, and no data sent to BuBird servers.
✓ Free developer tool✓ No account required✓ Browser-based utility✓ Fast results✓ Mobile friendly
Plain Text
This tool runs in your browser and does not upload your data to BuBird servers.
How To Use
How to Use Base64 Encoder & Decoder
1
Choose Encode or Decode
Select whether you want to encode plain text to Base64 or decode a Base64 string back to text.
2
Enter Your Input
Paste your text string (to encode) or your Base64 string (to decode) into the input area.
3
Get the Result
The output appears instantly. For encoding, you see the Base64 string; for decoding, you see the original text.
4
Copy the Output
Click the copy button to copy the result to your clipboard for use in your code or config.
Example
Example Use
Embedding Credentials in an API Header
Basic authentication requires encoding credentials in the format username:password as Base64. For example, encoding admin:secret produces YWRtaW46c2VjcmV0, which is sent as the Authorization: Basic YWRtaW46c2VjcmV0 header value. Paste the result directly into your HTTP client or code.
Use Cases
Who Uses Base64 Encoder & Decoder
Backend Developers
Encode authentication credentials, API tokens, and binary payloads for HTTP headers and JSON fields.
Web Developers
Embed small images as data URIs in HTML and CSS using Base64 to reduce HTTP requests.
API Integrators
Decode Base64-encoded responses from APIs to inspect the underlying data.
Email Engineers
Understand how MIME email attachments encode binary content as Base64 for transport.
QA Engineers
Verify Base64-encoded payloads in API tests match expected decoded values.
Students & Learners
Explore how Base64 works as part of understanding web authentication and data encoding.
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FAQ
Frequently Asked Questions
What is Base64 encoding?
Base64 is an encoding scheme that converts binary or text data into a string of ASCII characters. It is widely used to safely embed binary data in text-based formats like JSON, XML, HTML, and email.
Is Base64 encoding the same as encryption?
No. Base64 is an encoding format, not encryption. Anyone who sees a Base64 string can decode it immediately. Do not use Base64 to secure sensitive data — use proper encryption instead.
Does this tool upload my data?
No. All encoding and decoding is performed locally in your browser using JavaScript. Your input never leaves your device and is never sent to BuBird servers.
Can I encode binary files with this tool?
This tool is optimised for text input. For binary file encoding, use the file upload option in the tool where available.
Why does Base64 output end with == padding?
Base64 encodes data in groups of 3 bytes. When the input length is not a multiple of 3, padding characters (=) are added to complete the final group to maintain consistent block sizes.