Base64 Converter: Encode & Decode

Transform text, images, and files into Base64 strings or back to raw data. Our base64 encode online tool is built for developers who need fast, secure conversion.

AI Overview

Base64 Encoding is a process that converts binary data into a text format. It is used to embed images in CSS, transmit JWT tokens, and handle email attachments. Every 3 bytes of data are turned into 4 characters, resulting in a roughly 33% increase in size compared to the original file.

What is Base64 Encoding?

Base64 is an encoding scheme that represents binary data using only 64 printable ASCII characters. This makes it possible to send files and images through systems that only support text, such as HTML, CSS, and JSON.

Developer Tip: Use URL-Safe Base64 when passing data in a web address. Standard Base64 uses symbols like + and /, which can break URLs.

How to Use Base64 for Images

You can use base64 encode online to convert small icons into "Data URIs." This allows you to paste the image data directly into your CSS code, reducing the number of server requests and making your website load faster.

Common Use Cases for 2026

  • JWT Tokens: JSON Web Tokens use Base64 to transmit user claims between a client and a server.
  • Email Attachments: Most email systems convert files to Base64 to ensure they aren't corrupted during transmission.
  • API Data: Send binary files (like PDFs) as text strings in REST API requests.
  • Secrets: Kubernetes and other dev tools use Base64 to handle sensitive configuration strings.

Frequently Asked Questions

Is Base64 the same as encryption?
No. Base64 is Encoding, not Encryption. Anyone can decode it instantly without a key. Never use it for passwords.

Why is my file bigger?
Base64 encoding adds 33% overhead. A 1MB file will become roughly 1.33MB after encoding.

Can I convert images back to files?
Yes. Our base64 decode online tool can take a string and recreate the original image or file for download.