Base64 Encoder & Decoder - Encode Decode Text Online Free
Encode text to Base64 or decode Base64 strings instantly
About this tool
A free online Base64 encoder and decoder that lets you instantly convert between plain text and Base64 encoding. Base64 is a widely-used encoding scheme that converts binary data into a text format using 64 ASCII characters, making it safe for transmission through text-based systems like email, APIs, and HTTP headers.
Our tool supports two operations: Encode (convert text to Base64) and Decode (convert Base64 back to text). Simply choose your mode, paste your content, click the button, and get instant results. The tool handles special characters, Unicode, and multi-line content perfectly, preserving formatting while ensuring accurate encoding/decoding.
Beyond simple text input, the tool also supports file uploads, so you can encode or decode the contents of text files directly. This is especially useful for handling configuration files, API responses, or any text-based content. The tool shows you real-time size comparison so you can see exactly how much the encoding expands your data (Base64 typically increases size by about 33%).
How to use this tool
Choose your mode
Select "Encode to Base64" to convert text to Base64, or "Decode from Base64" to convert Base64 back to text.
Paste your content
Enter text in the left panel, or use "Choose File" to upload a text file. The tool reads the file content automatically.
Click Encode or Decode
The tool instantly converts your content and displays the result in the right panel. Check the size comparison to see the data size change.
Copy your result
Click the Copy button to copy the output to your clipboard, then paste it wherever you need it—APIs, code, documentation, etc.
Frequently Asked Questions
What is Base64 and why is it used?
Base64 is an encoding scheme that converts any data (binary or text) into a string using 64 safe ASCII characters. It's used to safely transmit binary data over text-based systems like email and HTTP. For example, API authentication often encodes credentials as "username:password" → Base64 → HTTP header.
Why does Base64 make data larger?
Base64 encoding converts 3 bytes of data into 4 Base64 characters, increasing size by approximately 33%. This is the trade-off for having text-safe, transmissible data. Despite the size increase, Base64 remains essential for many applications like data URIs, email attachments, and API communications.
Can I encode/decode binary files with this tool?
This tool works best with text files. While it can technically encode binary files you upload, the encoded output may be extremely long and difficult to work with. For true binary-to-Base64 conversion, use command-line tools or programming libraries designed for binary data.
How do I use Base64 for authentication?
Basic HTTP authentication encodes "username:password" as Base64 and sends it in the Authorization header as "Authorization: Basic base64(username:password)". This tool lets you generate the Base64-encoded credential string needed for testing and debugging API calls.
Is Base64 encoding secure?
No. Base64 is encoding, not encryption. The encoded string is easily decoded. Never use Base64 alone for sensitive data like passwords—it provides no security, only text safety. Always combine with HTTPS/TLS encryption for secure transmission of sensitive information.