Base64 Encoder/Decoder
Easily encode text to Base64 or decode Base64 to text with this free online tool. Perfect for developers working with data URIs, API authentication, or email attachments.
Text to Encode
Base64 Result
Image Preview
What is Base64 Encoding?
Base64 is a binary-to-text encoding scheme that represents binary data in an ASCII string format by translating it into a radix-64 representation. It’s commonly used when there’s a need to encode binary data that needs to be stored and transferred over media that are designed to deal with text.
Base64 is particularly useful in a number of scenarios:
- Embedding binary data (like images) in text-based formats such as HTML, CSS, or JSON
- Sending binary data through email systems that only support text
- Storing complex data in XML or JSON format
- Encoding data in URLs where certain characters are restricted
- Basic authentication in web applications (username:password encoded in Base64)
How Base64 Works
Base64 encoding works by dividing the binary data into 6-bit pieces and converting each piece into a corresponding character from a 64-character alphabet. The standard Base64 alphabet includes:
- Uppercase letters: A-Z (26 characters)
- Lowercase letters: a-z (26 characters)
- Numbers: 0-9 (10 characters)
- Special characters: + and / (2 characters)
The = character is used for padding when the input length is not divisible by 3 bytes.
Features
Two-Way Conversion
Easily convert text to Base64 and decode Base64 back to text with a simple click.
URL-Safe Encoding
Option to use URL-safe characters (- and _) instead of standard Base64 characters (+ and /).
Image Support
Decode Base64 image strings and view the image preview directly in the browser.
Developer Friendly
Perfect for developers working with data URIs, API authentication, or email attachments.
How to Use
Encoding Text to Base64
- Select the “Encode to Base64” tab
- Enter or paste the text you want to encode
- Choose whether you want URL-safe encoding
- Click the “Encode to Base64” button
- Copy or download the resulting Base64 string
Decoding Base64 to Text
- Select the “Decode from Base64” tab
- Enter or paste the Base64 string you want to decode
- Click the “Decode from Base64” button
- View the decoded text result
- If the result is an image, you’ll see a preview below the text area
Common Use Cases for Base64
Data URIs
Base64 encoding is commonly used in data URIs to embed images, fonts, and other files directly in HTML, CSS, or JavaScript files, reducing HTTP requests.
API Authentication
Basic authentication in web APIs uses Base64 to encode username and password combinations, though this should always be used with HTTPS for security.
Email Attachments
MIME encoding uses Base64 to encode binary email attachments into ASCII text format for transmission through email systems.
JSON Web Tokens
JWTs use Base64URL encoding (a URL-safe variant of Base64) to encode header, payload, and signature components for secure data transmission.
Frequently Asked Questions
What is the difference between Base64 and Base64URL?
Base64URL is a variant of Base64 that uses URL-safe characters. It replaces the + character with – and the / character with _, making it safe to use in URLs and filenames. Our tool offers an option to use URL-safe encoding.
Is Base64 encoding a form of encryption?
No, Base64 is not encryption. It’s simply an encoding scheme that transforms binary data into text. It doesn’t provide any security or confidentiality, as anyone can decode Base64 data without a key.
Why does Base64 encoding increase the size of my data?
Base64 encoding increases data size by approximately 33% because it represents 3 bytes of binary data with 4 bytes of ASCII text. This overhead is the trade-off for making binary data compatible with text-based systems.
Can I encode images with this tool?
This tool is designed for text encoding/decoding. For image encoding, you would typically need to first convert the image to a binary format, which is beyond the scope of this tool. However, you can decode Base64 strings that represent images, and our tool will display a preview.
What are those equals signs (=) at the end of Base64 strings?
The equals signs are padding characters. Since Base64 encodes data in groups of 3 bytes, if your data length isn’t divisible by 3, padding characters are added to make it fit. One or two equals signs may appear at the end of a Base64 string.
Is my data secure when using this tool?
Yes, all processing happens directly in your browser. Your data is never sent to our servers, ensuring complete privacy. However, remember that Base64 itself is not encryption, so sensitive data should be properly secured using encryption before transmission.