# Base64 Encode & Decode — Free Online Tool
https://base64.usetool.org/

> Base64 is a free, privacy-first online tool for encoding and decoding Base64 data. Supports text-to-Base64, Base64-to-text, and file-to-Base64 conversions. No signup, no ads, no server processing — everything runs in your browser.

## Features
- Encode plain text to Base64
- Decode Base64 back to plain text
- File to Base64 (data URI) conversion
- Real-time encoding/decoding as you type
- One-click copy to clipboard
- Dark mode support
- Mobile responsive design
- Works offline after first load

## Use Cases
Developers encoding API credentials, embedding images as data URIs in HTML/CSS, encoding binary data for JSON payloads, decoding Base64-encoded JWT tokens, encoding email attachments, debugging encoded strings in logs.

## Limitations
No batch file encoding. No URL-safe Base64 variant toggle. No binary file decoding to download. No API — all processing is client-side in the browser.

## Technical
Built with Astro 5 (static site generator), Preact + Signals (~4KB interactive island), Tailwind CSS. Uses native browser btoa()/atob() APIs. Text never leaves the browser. Part of the UseTool suite at usetool.org.