Online Base64 Encoder and Decoder
Convert Text to Base64 and Base64 to Text
Our free online Base64 tool allows you to encode and decode text instantly. All processing happens in your browser, ensuring your data remains private and secure. Use it for email attachments, data URIs, or any Base64 conversion needs.
Base64 Encoder
About Base64 Encoding:
- Base64 encoding increases the data size by approximately 33%
- Commonly used to encode binary data in email attachments
- Useful for embedding images directly in HTML/CSS as data URIs
- All processing happens in your browser - your data stays private
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. The term "Base64" originates from the specific MIME content transfer encoding. Each Base64 digit represents exactly 6 bits of data, so three 8-bit bytes (24 bits) can be represented by four 6-bit Base64 digits.
Common Uses of Base64
Email Attachments
Base64 is used to encode binary files in email attachments.
Data URLs
Embedding images and other files directly in HTML or CSS files using the data URI scheme.
XML and JSON
Encoding binary data for inclusion in XML and JSON documents.
Cookies and Web Storage
Storing binary data in cookies or web storage where only text is allowed.
Basic Authentication
HTTP Basic Authentication credentials are Base64-encoded.
How to Use This Tool
- Enter or paste the text you want to encode or decode in the input field.
- Select the operation mode (Encode or Decode).
- View the result instantly in the output field.
- Click the "Copy" button to copy the result to your clipboard.
Why Choose Our Base64 Tool?
Privacy-Focused
All encoding and decoding occurs in your browser - your data never leaves your device.
Real-time Processing
Instant results as you type, with no page reloads required.
User-Friendly Interface
Clean, intuitive design that's easy to use.
No Installation Required
Works directly in your browser without any plugins or downloads.
Mobile-Friendly
Fully responsive design that works on all devices.
Technical Details about Base64
Base64 uses a set of 64 characters to represent binary data: uppercase letters A-Z (26 characters), lowercase letters a-z (26 characters), numbers 0-9 (10 characters), and two additional characters that vary depending on the specific Base64 variant (commonly "+" and "/" with "=" used for padding).
The encoding process converts each group of three bytes (24 bits) into four Base64 characters (each representing 6 bits). If the input data length is not a multiple of three, padding is added to ensure the encoded output length is a multiple of four characters.
Base64 vs URL-safe Base64
Standard Base64
Uses the full 64-character set including '+' and '/' which have special meanings in URLs.
URL-safe Base64
Replaces '+' with '-' and '/' with '_' making the encoded string safe to use in URLs.
Common Issues with Base64
Increased Size
Base64 encoding increases the data size by approximately 33%.
Padding Characters
The '=' padding characters at the end of Base64 strings can sometimes cause issues in certain contexts.
Character Set Confusion
Different variants of Base64 use slightly different character sets, which can lead to compatibility issues.
Non-Binary Data Confusion
Attempting to decode text that isn't valid Base64 can lead to errors or unexpected results.
Frequently Asked Questions
Is Base64 encryption?
No, Base64 is not encryption - it's an encoding scheme. It doesn't provide any security or confidentiality, as anyone can decode Base64 data. If you need to secure your data, you should use proper encryption algorithms like AES or RSA in addition to any encoding.
Why do I see "=" signs at the end of Base64 strings?
The "=" characters are padding used to ensure the encoded output length is a multiple of 4. Since Base64 converts 3 bytes into 4 characters, if your input length is not divisible by 3, padding is added. You may see one or two "=" characters at the end, depending on the remainder when dividing the input length by 3.
Can I encode binary files like images with this tool?
This specific tool is designed for text-to-Base64 and Base64-to-text conversion. For binary files like images, you would need a file-to-Base64 converter. However, you can use the resulting Base64 string from other tools and decode it here if needed.
What's the difference between Base64 and Hex encoding?
Base64 uses 64 characters (A-Z, a-z, 0-9, + and /) to represent binary data, while Hex (hexadecimal) uses 16 characters (0-9 and A-F). Base64 is more space-efficient as it represents 6 bits per character, compared to 4 bits per character in Hex encoding. This means Base64 encoded strings are about 33% shorter than the same data in Hex format.
Why am I getting errors when decoding?
Errors during decoding usually occur because the input is not valid Base64. Make sure the string you're trying to decode contains only valid Base64 characters (A-Z, a-z, 0-9, +, /, and =). Also, the length of a Base64 string should be a multiple of 4 characters. Common issues include missing padding, extra whitespace, or line breaks in the input.
How do I use Base64 in a data URI?
To use Base64 in a data URI (for embedding images in HTML/CSS), follow this format: data:[<MIME-type>][;base64],<Base64-encoded-data>. For example, a Base64-encoded JPEG image would be: data:image/jpeg;base64,/9j/4AAQSkZJRg... You can then use this string in img src attributes or CSS background-image properties.