What is Base64 Encoding?
Base64 is an encoding scheme that converts binary data into 64 printable ASCII characters (A-Z, a-z, 0-9, +, /). It was developed to safely transmit binary data in text-only environments such as email attachments, web API communication, image-to-Base64 conversion (Data URIs), and JWT token payloads. It is defined by the RFC 4648 standard.
This free online Base64 converter encodes or decodes text, images, and files in real-time. It supports URL-Safe Base64, file upload, image preview, drag-and-drop, and conversion history (up to 10 entries). Full UTF-8 and Unicode support with all processing happening locally in your browser — your data never leaves your device.
Key Features
Real-time Encoding/Decoding
Enter text to instantly convert to Base64, or paste a Base64 string to restore the original text. Fully supports UTF-8 encoding.
URL-Safe Mode
Supports URL-Safe Base64 conversion using -, _ instead of +, /, =. Safe to use in URL parameters and filenames.
File Upload & Image Preview
Upload files to automatically convert to Base64. Image files get a Data URI format preview.
Drag & Drop
Drag files into the input area for instant Base64 conversion. Fast and intuitive file processing.
How to Use
- Select Mode — Choose encode (text to Base64) or decode (Base64 to text) mode at the top.
- Enter Text or Upload File — Type or paste text to convert, or add files via the upload button or drag and drop.
- Set Options — Enable URL-Safe mode if you need to use the result in URL parameters.
- Convert — Click the convert button and the result appears instantly.
- Copy Result — Click the copy button to copy the conversion result to your clipboard.
Use Cases
API Development (Basic Auth)
In HTTP Basic Authentication, username:password is Base64 encoded and sent via the Authorization header. An essential encoding method for API testing.
Email Attachments
The MIME protocol uses Base64 to convert binary attachments into text format. It is the standard encoding method for email systems.
Data URI Image Embedding
Convert images to Base64 and embed them directly in HTML/CSS to display images without additional HTTP requests. Effective for small icons and logos.
Data Transfer & Storage
Use Base64 encoding when you need to include binary data in text-based formats like JSON or XML. Used in JWT tokens, configuration files, and more.
FAQ
Q. Is Base64 encoding encryption?
No, Base64 is encoding, not encryption. Anyone can easily decode it, so it's not suitable for protecting sensitive data. It should only be used for data format conversion purposes.
Q. What is URL-Safe Base64?
URL-Safe Base64 is a variant that replaces unsafe URL characters (+, /, =) with safe characters (-, _). It's useful when using Base64 strings in URL parameters or filenames.
Q. Why does Base64 encoding increase size?
Base64 converts 6 bits into 8-bit ASCII characters, so the encoded data size increases by approximately 33%. (3 bytes → 4 characters)
Q. What is the difference between URL-Safe and standard Base64?
Standard Base64 uses +, /, and = characters, which have special meanings in URLs. URL-Safe Base64 replaces + with -, / with _, and removes padding (=), making it safe to use in URLs and filenames.
Privacy Notice
This Base64 encoder/decoder processes all data within your browser. The text you enter or files you upload are never sent to any server. No information is stored or collected. You can safely convert even sensitive data.