Base64 File Converter

Base64 is a binary-to-text encoding scheme that represents binary data using 64 printable ASCII characters (A–Z, a–z, 0–9, +, /). It increases the data size by about 33% but makes binary data safe to transmit over text-based protocols.

Base64 encoding is commonly used to embed images in HTML or CSS (data URIs like data:image/png;base64,...), encode file attachments in emails (MIME), transmit binary data in JSON APIs, and store binary data in databases or configuration files that expect text.

This tool supports encoding any file type — images (JPEG, PNG, GIF, WebP, SVG), documents (PDF, Word), audio, video, and more. The encoding is performed using the browser's native FileReader.readAsDataURL() API, which reads the file as a data URL and extracts the base64 portion.

For decoding, the tool takes a base64 string, decodes it to binary using atob(), and triggers a download using the Blob API. You specify the output filename and extension so the browser knows how to handle the file.

All processing happens entirely in your browser. Your files are never uploaded to any server. The tool works offline once the page is loaded. Large files (over 50MB) may cause the base64 output to be very large, which could impact browser performance.

You may also find our Base64 Encode / Decode, Hash Generator, and Text Encrypt / Decrypt helpful.