Base64 Encoder - Encode Text to Base64 Online

What is Base64 Encoding?

Base64 encoding is a binary-to-text encoding scheme that converts binary data into an ASCII string format. It represents binary data using 64 printable ASCII characters (A-Z, a-z, 0-9, +, and /), making it safe for transmission over media designed to handle text.

The encoding process takes 3 bytes (24 bits) of binary data and converts them into 4 Base64 characters (6 bits each). This results in approximately 33% overhead in data size.

Why use Base64?

• Data Transmission: Safely transmit binary data over text-based protocols like HTTP, email, or JSON
• Embedding Data: Include images, fonts, or other files directly in HTML, CSS, or JSON
• URL Safety: Encode data containing special characters for use in URLs
• Authentication: Used in Basic Authentication headers and API tokens
• Data Storage: Store binary data in text-only databases or configuration files

Base64 Encoding Examples

Plain Text:

Hello, World!

Base64:

SGVsbG8sIFdvcmxkIQ==

Plain Text:

admin:password123

Base64:

YWRtaW46cGFzc3dvcmQxMjM=

Plain Text:

{"name":"John","age":30}

Base64:

eyJuYW1lIjoiSm9obiIsImFnZSI6MzB9

Common Mistakes

1. Confusing Base64 with Encryption: Base64 is encoding, not encryption. It doesn’t provide security—anyone can decode it.

2. Forgetting Padding: Base64 strings may end with = or == for padding. Removing these can cause decoding errors.

3. Using Wrong Character Set: URL-safe Base64 uses - and _ instead of + and /. Mixing these causes errors.

4. Not Handling Line Breaks: Some implementations add line breaks after 76 characters. These must be removed before decoding.

5. Encoding Already Encoded Data: Double-encoding creates invalid output. Always check your input first.

FAQs

Q: Is Base64 encoding secure?
A: No, Base64 is not encryption. It’s easily reversible and should not be used for security purposes.

Q: Why does Base64 increase file size?
A: Base64 uses 4 characters to represent 3 bytes, resulting in ~33% size increase.

Q: Can I encode any type of data?
A: Yes, Base64 can encode any binary data including text, images, files, and more.

Q: What’s the difference between Base64 and Base64URL?
A: Base64URL replaces + with - and / with _ to make the output URL-safe without percent-encoding.

Q: Do I need to encode data before sending via HTTP?
A: Not always. Modern APIs handle binary data, but Base64 is useful for JSON payloads or when the API expects text.