Base64 Encoder/Decoder
Easily convert text or files to Base64 format, or decode Base64 strings back to their original form.
What is Base64 Encoding?
Base64 is a group of binary-to-text encoding schemes that represent binary data (like images, files, or executable code) in an ASCII string format. It is called "Base64" because it uses a set of 64 characters to represent data: A-Z, a-z, 0-9, +, and /. It also uses = for padding at the end of the string.
Computers store data in binary (0s and 1s). However, many older protocols (like email via SMTP) were designed to handle only plain text. If you try to send a raw image or a binary file through these systems, the data can get corrupted because some binary patterns might be interpreted as control characters (like "end of file" or "new line").
Base64 solves this by translating that binary data into a safe, printable text format that can travel through any system without modification.
Common Uses for Base64
1. Data URIs (Images in HTML/CSS)
Web developers often use Base64 to embed small images (like icons or logos) directly into HTML or CSS files instead of referencing an external image file. This reduces the number of HTTP requests the browser has to make, potentially speeding up page load times.
Example: <img src="data:image/png;base64,iVBORw0KGgo..." />
2. Email Attachments (MIME)
When you send an email with a PDF or JPEG attachment, your email client automatically encodes that file into a Base64 string. The receiving email server decodes it back into the original file for the recipient to view.
3. Basic Authentication
In HTTP Basic Authentication, the username and password are joined by a colon (user:password) and then encoded in Base64 before being sent in the HTTP header (Authorization: Basic dXNlcjpwYXNzd29yZA==). Note: This is encoding, not encryption, and can be easily decoded.
Base64 vs. Encryption: A Critical Distinction
It is a common misconception that Base64 is a way to "hide" or "encrypt" data. Base64 is NOT encryption.
- Encoding (Base64): Transforms data into a new format so it can be safely transmitted. It requires no key and can be decoded by anyone.
- Encryption (AES, RSA): Scrambles data to keep it secret. It requires a private key or password to decrypt.
Never use Base64 to store sensitive data like passwords or credit card numbers unless it is also encrypted.
How This Tool Works
Our **Base64 Encoder/Decoder** runs entirely in your web browser using JavaScript. This offers two major benefits:
- Speed: Because the data doesn't have to travel to a server and back, the conversion happens instantly.
- Privacy: Your data (files, images, or text) never leaves your computer. It is processed locally, ensuring total confidentiality.
Performance Note
Base64 encoding increases the size of the data by approximately **33%**. For example, a 100KB image will become a ~133KB Base64 string. While useful for small icons, encoding large images in Base64 can actually slow down your website by bloating the HTML size. Use it wisely!