Convert text and files to Base64 format or decode Base64 strings instantly — secure, fast, and 100% browser-based.
Instant, private, and free — no account, no install, nothing stored.
Conversion happens in milliseconds with no server round-trips.
All processing is local — nothing is ever transmitted to a server.
Paste raw text or upload any file type up to 5 MB for encoding.
Switch between encode and decode mode with a single click at any time.
Embed images directly in CSS/HTML as data URIs to eliminate extra HTTP requests.
MIME email standards require file attachments to be Base64-encoded before sending.
Prepare binary data like images for transmission in JSON API request bodies.
HTTP Basic Auth credentials are transmitted as Base64-encoded username:password.
Base64 is a group of binary-to-text encoding schemes that represent binary data in an ASCII string format. It was designed to allow binary content to pass through systems that only handle text. Common use cases include embedding image files directly in HTML or CSS using data URIs, attaching binary files to emails using MIME encoding, and transmitting binary payloads in JSON REST APIs where the format must be text-only.
This tool uses JavaScript's built-in btoa() function to encode strings to Base64, and atob() to decode them. For file uploads, the FileReader API reads the file as a data URL, and the Base64 portion is extracted from the result. Everything happens in your browser tab with no network requests — making it both fast and completely private.
Base64 encoding and encryption are completely different things. Base64 is a reversible encoding format — anyone with the Base64 string can immediately decode it with no key. It is not a security measure. Encryption (like AES or RSA), on the other hand, requires a secret key to decode. Do not use Base64 encoding to protect sensitive data — use proper encryption instead.