Encode and decode Base64 instantly — everything runs in your browser.
Base64 Encoder / Decoder is a free online tool that converts text to Base64 encoding and back. Base64 is a binary-to-text encoding scheme that represents binary data in an ASCII string format, commonly used in web development, email systems, and data transmission. The encoder converts any text input — including Unicode and UTF-8 characters — into a Base64 encoded string. The decoder reverses the process, converting Base64 strings back to their original text representation. Both operations happen instantly as you type or click. Base64 encoding is used extensively in web development for embedding images in CSS and HTML (data URIs), encoding authentication credentials in HTTP headers (Basic Auth), transmitting binary data in JSON APIs, encoding email attachments in MIME format, and storing binary data in text-based formats like XML or JSON. Everything runs entirely in your browser using JavaScript. Your data is never sent to any server, making it safe for encoding sensitive information like API keys, authentication tokens, and personal data. There are no size limits, no usage restrictions, and no account required. Common use cases include encoding images for inline CSS, preparing data for API requests, decoding Base64 strings from API responses, encoding credentials for HTTP Basic Authentication, and converting binary data for storage in text databases. The tool handles both standard Base64 and URL-safe Base64 variants. For related tools, check out the URL Encoder for percent-encoding URLs, the Image to Base64 converter for encoding images, or the SVG to Base64 tool for embedding SVG graphics.