Base64 Encode/Decode
Encode or decode Base64 text instantly with this free online converter. Supports UTF-8, Unicode, and special characters for web development and data transfer.
About This Calculator
The Base64 Encode/Decode tool lets you instantly convert text to and from Base64 encoding. Developers use it daily for working with data URIs, JSON web tokens (JWTs), email attachments, API payloads, and storing binary data in text-based formats. It supports full UTF-8 Unicode including emojis and international characters.
Base64 works by converting every 3 bytes of binary data into 4 ASCII characters using a 64-character lookup table (A-Z, a-z, 0-9, +, /). The tool uses the standard RFC 4648 Base64 encoding with btoa() and atob() functions via UTF-8-safe conversion. The breakdown section shows input size, output size, and the ~33% overhead that Base64 introduces. The chart visualizes the size comparison between input and output.
Regional Notes
India: Used by Indian developers working with UPI APIs, IRCTC integrations, Digilocker document encoding, and general web development with Hindi/regional language Unicode text.
United States: Commonly used in JWT authentication, REST API development, email encoding (MIME), CSS data URIs, and binary-to-text conversion in frontend and Node.js applications.
United Kingdom: Used in UK fintech API integrations, Open Banking data encoding, NHS digital health record transfers, and general software development.
Frequently Asked Questions
What is Base64 encoding?
Base64 is a binary-to-text encoding scheme that represents binary data in an ASCII string format by converting it into a radix-64 representation. It is commonly used for transmitting data over media that are designed to handle textual data, such as email attachments and JSON web tokens.
How do I encode text to Base64?
Enter your text in the input field, select Encode mode, and click Calculate. The tool converts your UTF-8 text to a Base64 encoded string that can be safely used in URLs, JSON, and data URIs.
How do I decode Base64 back to text?
Paste the Base64 string into the input field, select Decode mode, and click Calculate. The tool will convert it back to the original UTF-8 text if the input is valid Base64.
Does this tool support Unicode and special characters?
Yes, the Base64 Encode/Decode tool fully supports UTF-8 encoding, including Unicode characters, emojis, and special symbols from all languages including English, Hindi, Chinese, Arabic, and more.
Why does Base64 increase the data size?
Base64 encoding increases data size by approximately 33% because every 3 bytes of binary data are encoded as 4 ASCII characters. The breakdown section shows the exact input and output sizes along with the overhead percentage.
Is this tool free to use?
Yes, the Base64 Encode/Decode converter is completely free with no registration, usage limits, or hidden charges. You can encode or decode as much text as you need.
Can I share my encoded or decoded results?
Yes, the URL automatically saves your input and mode settings so you can bookmark or share the exact calculation link with others for reference.
How does the byte overhead calculation work?
The overhead percentage compares the output size against the input size. For encoding it shows how much larger the Base64 string is, and for decoding it shows the compression ratio when converting back to raw bytes.