Base64 Encoder/Decoder
Convert text to Base64 encoding or decode Base64 strings. Perfect for data transmission, embedding images, and API authentication.
About Base64 Encoding
Base64 is a binary-to-text encoding scheme that converts binary data into ASCII text format. It uses 64 different ASCII characters (A-Z, a-z, 0-9, +, /) to represent data, making it safe for transmission over text-based protocols and storage in text-based formats.
Why Use Base64?
📧 Email Attachments
Encode binary files for safe transmission through SMTP and other email protocols
🖼️ Data URIs
Embed images directly in HTML/CSS using data:image/png;base64,... format
🔐 API Authentication
Encode credentials for HTTP Basic Authentication headers
📝 JSON Data
Store binary data in JSON format without special character issues
How Base64 Works
Base64 encoding works by taking binary data and converting it into groups of 6 bits. Each 6-bit group is then mapped to one of 64 ASCII characters. Three bytes (24 bits) of binary data are converted into four Base64 characters.
Encoding Example
Base64 Character Set
| Range | Characters | Description |
|---|---|---|
| 0-25 | A-Z | Uppercase letters |
| 26-51 | a-z | Lowercase letters |
| 52-61 | 0-9 | Digits |
| 62 | + | Plus sign |
| 63 | / | Forward slash |
| Padding | = | Used for padding when needed |
Common Use Cases
- ✓Image Embedding: Convert images to Base64 for inline HTML/CSS usage
- ✓HTTP Headers: Encode credentials for Basic Authentication
- ✓JWT Tokens: JSON Web Tokens use Base64 URL encoding
- ✓File Uploads: Send files through JSON APIs
- ✓URL Parameters: Encode complex data in query strings
- ✓Email MIME: Encode attachments in MIME format
Advantages & Disadvantages
✓ Advantages
- • Safe for text protocols (HTTP, SMTP, JSON)
- • Reversible encoding/decoding
- • Wide browser and language support
- • Handles binary data reliably
- • No special character issues
✗ Disadvantages
- • Increases data size by ~33%
- • Not encryption (data is visible)
- • Slightly slower processing
- • Not suitable for large files
- • Can't be indexed/searched
Frequently Asked Questions
Is Base64 encryption?
No, Base64 is encoding, not encryption. It's easily reversible and provides no security. Use encryption algorithms (AES, RSA) for security, not Base64.
Why does Base64 increase file size?
Base64 converts 3 bytes (24 bits) into 4 characters, increasing size by approximately 33%. This overhead is the cost of representing binary data as safe ASCII text.
What is the = padding for?
The = character is used for padding when the input length isn't divisible by 3. It ensures the encoded string length is always divisible by 4.
Can I encode images to Base64?
Yes, but this tool is for text. For images, use image-to-Base64 converters that read binary files. The output can be used in data URIs: data:image/png;base64,...
Is Base64 safe for URLs?
Standard Base64 uses + and / which aren't URL-safe. Base64 URL encoding replaces + with - and / with _ for safe use in URLs. Remove padding = when using in URLs.