About Base64 Encoder / Decoder
The Base64 Encoder/Decoder provides a simple, private, browser-based way to encode text and files into Base64 and to decode Base64 back into human-readable text or downloadable files. It relies on native browser APIs like FileReader and atob/btoa (and modern TextEncoder/TextDecoder) to keep all processing local and fast.
Key features
- Encode plain text to Base64 and copy with one click.
- Decode Base64 to text or download decoded bytes as a file.
- Upload files and encode them to Base64 for embedding in data URIs.
- Client-side only: nothing is sent to a server — ideal for sensitive data.
- Simple UI optimized for mobile and desktop with square controls.
How it works
Base64 converts binary data into ASCII text using a 64-character alphabet. It's commonly used to embed images in HTML/CSS (data: URIs), include binary data in JSON, or quickly transmit small files in text-only channels. When decoding, the tool will attempt to present the output as UTF-8 text; if the decoded bytes are non-textual, you can download them as a file instead.
FAQ
Is my data uploaded?
No — all encoding and decoding happens in your browser. If you need stronger guarantees, run the page offline or in a private window.
What file sizes are supported?
File size limits are determined by your device and browser. Small to moderate files (a few MB) are typical; very large files may be slow to process in-memory.
High-value keywords
base64 encoder, base64 decoder, encode to base64, decode base64, base64 file encoder