Base64 File Encoder — Encode Files to Base64 Online
Encode any file to a Base64 string or decode a Base64 string back to a downloadable file. Supports drag-and-drop, file info display, and one-click copy. 100% client-side — your files never leave your device.
How to Use the Base64 File Encoder
- Encode: Drag and drop a file or click the upload area to select a file.
- The file is automatically converted to Base64 and displayed in the output textarea.
- Copy the Base64 string to your clipboard or download it as a .txt file.
- Decode: Switch to the Decode tab, paste a Base64 string, and provide a file name.
- Click Decode & Download to save the decoded file to your device.
Why Use This Base64 File Encoder
Base64 encoding is essential for embedding binary data in text formats — like embedding images in HTML/CSS, sending files via email, or storing binary data in JSON APIs.
This tool provides instant encoding/decoding, drag-and-drop support, file metadata display, and complete privacy since everything runs in your browser.
Frequently Asked Questions
Base64 is a binary-to-text encoding scheme that represents binary data as an ASCII string. It's commonly used to embed files in HTML, CSS, JSON, or XML.
The tool runs in your browser's memory. For best performance, files under 50MB are recommended. Very large files may slow down your browser.
No. All encoding and decoding happens entirely in your browser using the FileReader API. Your files never leave your device.
Use Cases
Embedding Images in CSS
Convert images to Base64 data URIs for embedding directly in CSS or HTML without separate file requests.
Email Attachments
Encode files to Base64 for embedding binary data in email bodies or API payloads that only accept text.
API Data Transfer
Send file data in JSON REST APIs by encoding files as Base64 strings in request/response bodies.
Data URL Generation
Create data URIs for inline assets in SVGs, HTML emails, or single-file web applications.