Base64 Encoder / Decoder
Encode and decode Base64 data online
All encoding and decoding is done locally in your browser. Your data never leaves your device.
About Base64 Encoder / Decoder
Base64 is a binary-to-text encoding scheme that converts binary data into an ASCII string format. This tool allows you to easily encode text to Base64 or decode Base64 strings back to plain text.
Base64 encoding is widely used in web development, email systems, data transmission, and embedding binary data in text formats like JSON or XML. It's particularly useful when you need to transmit binary data over text-based protocols.
Our Base64 encoder/decoder supports both standard Base64 and URL-safe Base64 encoding, making it versatile for various use cases including web URLs, APIs, and data serialization.
All encoding and decoding operations are performed entirely in your browser using JavaScript - your data remains private and never leaves your device.
How to Use the Base64 Tool
- Encoding Text to Base64:
- Enter or paste your plain text in the input field
- Click the "Encode to Base64" button
- The encoded Base64 string will appear in the output field
- Use the "Copy" button to copy the result to your clipboard
- Decoding Base64 to Text:
- Paste your Base64-encoded string in the input field
- Click the "Decode from Base64" button
- The decoded plain text will appear in the output field
- URL-safe Base64:
- Check the "URL-safe Base64" option before encoding
- This replaces + with - and / with _ making it safe for URLs
- Padding characters (=) are also handled appropriately
- Downloading Results: Click the "Download" button to save the output as a text file
- Clearing Data: Use the "Clear" button to reset both input and output fields
Key Terms & Concepts
What is Base64?
Base64 is an encoding scheme that converts binary data into a text format using 64 different ASCII characters. These characters include A-Z, a-z, 0-9, and two additional characters (+ and / in standard Base64, or - and _ in URL-safe Base64).
Standard vs URL-safe Base64
Standard Base64 uses + and / characters, which can cause issues in URLs and file names as they have special meanings. URL-safe Base64 replaces these with - and _ respectively, making the encoded string safe for use in URLs without additional encoding.
Base64 Padding
Base64 encoding may add one or two = (equals) characters at the end for padding to ensure the encoded string length is a multiple of 4. Some implementations may omit this padding in URL-safe variants.
Character Encoding (UTF-8)
This tool uses UTF-8 character encoding by default, which means it can properly handle special characters, emojis, and characters from various languages before converting them to Base64.
Why Not Use Base64 for Encryption?
Base64 is an encoding method, not encryption. It makes data unreadable to casual observers but provides no security. Anyone can decode Base64 strings. Never use Base64 alone to protect sensitive information - use proper encryption instead.
Common Use Cases for Base64
- Email Attachments: Email protocols use Base64 to encode binary file attachments into text format for transmission over SMTP.
- Data URLs: Embed images and other files directly in HTML or CSS using data:image/png;base64,... format.
- API Authentication: Many APIs use Base64 to encode authentication credentials in HTTP headers (e.g., Basic Authentication).
- JSON and XML: Embed binary data like images or files within JSON or XML documents which only support text.
- Web Tokens: JWT (JSON Web Tokens) use Base64URL encoding for their header and payload sections.
- Database Storage: Store binary data as text in databases that don't have native binary support.
- URL Parameters: Safely transmit complex data structures in URL query strings using URL-safe Base64.
- Configuration Files: Encode sensitive configuration values to prevent casual viewing in text files.
- QR Codes: Encode data before embedding in QR codes to handle special characters.
- Cookie Values: Store complex cookie values that might contain special characters.
Base64 Encoding Examples
Example 1: Simple Text
Input: Hello, World!
Base64 Output: SGVsbG8sIFdvcmxkIQ==
Example 2: Email with Special Characters
Input: [email protected]
Base64 Output: dXNlckBleGFtcGxlLmNvbQ==
Example 3: Unicode Characters
Input: こんにちは (Hello in Japanese)
Base64 Output: 44GT44KT44Gr44Gh44Gv
Example 4: URL-safe Encoding
Input: subjects?_d=1
Standard Base64: c3ViamVjdHM/X2Q9MQ==
URL-safe Base64: c3ViamVjdHM_X2Q9MQ
Important Notes & Best Practices
⚠️ Base64 is NOT Encryption
Base64 encoding is reversible and provides no security. Anyone can decode a Base64 string. Do not use it to protect passwords, API keys, or other sensitive information. Use proper encryption methods like AES for security.
📊 Size Increase
Base64 encoding increases data size by approximately 33%. For example, 3 bytes of binary data become 4 bytes of Base64 text. Consider this when encoding large amounts of data.
🔗 URL-safe Base64 for Web Use
When using Base64 in URLs, query parameters, or file names, always use URL-safe Base64 encoding to avoid issues with special characters that have meaning in URLs (+ and /).
✅ Character Encoding Matters
This tool uses UTF-8 encoding. When integrating with other systems, ensure they also use UTF-8 to avoid character corruption, especially with non-ASCII characters like emojis or international text.
🔒 Privacy & Security
All encoding and decoding operations are performed locally in your browser. No data is transmitted to any server, ensuring your sensitive information remains private.
💡 Performance Tips
- For very large files, consider using dedicated tools or libraries
- Base64 is best for small to medium-sized data (up to a few MB)
- If you need to encode many files, process them individually