Free Online Base64 Encoder & Decoder

Getting Started

Using the Base64 Encoder & Decoder is simple and efficient:

Basic Usage

1. Enter Text: Type or paste your text or Base64 string
2. Choose Mode: Select "Encode" to convert text to Base64, or "Decode" to convert Base64 to text
3. View Result: See the converted result instantly
4. Copy Output: Click copy button to use the result

What is Base64?

Base64 is an encoding scheme that converts binary data into ASCII text format using 64 printable characters (A-Z, a-z, 0-9, +, /). It's commonly used to:

• Transmit binary data over text-based protocols (HTTP, SMTP, JSON)
• Embed images and files in HTML, CSS, and emails
• Encode authentication credentials (Basic Auth)
• Store binary data in databases and configuration files
• Create data URIs for inline resources

Key Features

• Bidirectional Conversion: Encode text to Base64 and decode Base64 to text
• UTF-8 Support: Handle international characters and emojis correctly
• Real-time Conversion: See results as you type
• Error Detection: Clear messages for invalid Base64 input
• One-Click Copy: Copy results to clipboard instantly
• No Length Limit: Process data of any size
• URL-Safe Option: Support for URL-safe Base64 encoding
• Privacy Protected: All processing happens locally

Common Use Cases

API Development

• Basic Authentication: Encode username:password for HTTP Basic Auth
• API Tokens: Encode/decode API keys and tokens
• Binary Data in JSON: Transmit binary data in JSON payloads
• Webhook Signatures: Encode signature data

Web Development

• Data URIs: Create inline images and resources (data:image/png;base64,...)
• CSS Background Images: Embed small images in CSS
• HTML Email: Embed images in email templates
• Local Storage: Store binary data in browser storage

Data Transmission

• Email Attachments: MIME email encoding
• XML Data: Embed binary data in XML documents
• Configuration Files: Store binary data in text config files
• Database Storage: Store binary data in text fields

Security & Authentication

• HTTP Basic Auth: Encode credentials for Authorization header
• JWT Tokens: Decode JWT payload (Base64URL variant)
• Certificate Data: Encode/decode PEM certificates
• Encrypted Data: Transmit encrypted binary data as text

Base64 Variants

Standard Base64

Uses characters: A-Z, a-z, 0-9, +, / with = padding

• Most common variant
• Used in MIME, email, and general data encoding
• Example: SGVsbG8gV29ybGQh

URL-Safe Base64

Uses characters: A-Z, a-z, 0-9, -, _ (replaces + and /)

• Safe for use in URLs and filenames
• Used in JWT tokens and URL parameters
• May omit padding (=) characters

Best Practices

• Use Base64 for transmitting binary data over text protocols
• Don't use Base64 for encryption (it's encoding, not encryption)
• Be aware that Base64 increases data size by ~33%
• Use URL-safe Base64 for URLs and filenames
• Always specify UTF-8 encoding for text data
• Validate Base64 strings before decoding

Tips & Tricks

• Encode credentials for HTTP Basic Auth: base64("username:password")
• Create data URIs: data:image/png;base64,[encoded_image]
• Decode JWT tokens to inspect payload (middle section)
• Use for embedding small images in CSS to reduce HTTP requests
• Store binary data in JSON without escaping issues
• Test API authentication headers during development

Examples

Example 1: Basic Authentication

Input: admin:password123

Encoded: YWRtaW46cGFzc3dvcmQxMjM=

Usage: Authorization: Basic YWRtaW46cGFzc3dvcmQxMjM=

Example 2: Data URI

Small image encoded as Base64 can be embedded directly in HTML:

<img src="data:image/png;base64,iVBORw0KG..." />

Example 3: JSON Binary Data

Transmit binary data in JSON:

{"file": "SGVsbG8gV29ybGQh", "encoding": "base64"}