Base64 encode text or data in your browser for free. Paste any input and get the Base64 encoded string instantly. No signup or server upload required.
Base64 Encoder and Decoder is a free browser-based tool for converting text and binary data to and from Base64 encoding. Base64 represents binary data as ASCII characters, making it safe to include binary content in contexts that only handle text: embedding small images in CSS as data URLs, encoding binary API request and response payloads, storing binary data in JSON fields, and transmitting data through systems that may corrupt binary content. Users enter text or a Base64 string, choose encode or decode, and get the result instantly. The tool runs entirely in the browser with no data sent to a server. No account or installation is required, and the conversion is immediate for any input length. For complete results, URL Encoder / Decoder can encode and decode URL-encoded strings, Image to Base64 can convert images to Base64 data URIs for inline embedding, and Hash Generator can generate MD5, SHA-1, SHA-256, and SHA-512 hashes.
Base64 encoding is a foundational technique in web development, API integration, and data handling. The most common use case is encoding binary data for transmission in text-based formats. HTTP Basic Authentication sends credentials as a Base64-encoded "username:password" string in the Authorization header. Email attachments are Base64-encoded in the MIME format. Small images are sometimes embedded in CSS or HTML as Base64 data URLs to eliminate an HTTP request. JWT tokens use Base64url encoding for their header and payload segments. When debugging these systems, being able to quickly decode a Base64 string to inspect its contents, or encode a string to verify its correct Base64 representation, saves time compared to writing one-off code in the browser console. The tool handles both standard Base64 (using + and / characters) and URL-safe Base64 variants (using - and _ instead). It also handles padding with = characters correctly. For binary file encoding such as image data, the tool accepts binary input and returns the Base64 string. Note that Base64 encoding increases data size by approximately 33 percent because three bytes of binary data are represented as four ASCII characters. For large binary files, this overhead is a consideration when choosing whether to use Base64 encoding versus a binary transfer method. The tool runs free in the browser without installation and processes any input length immediately.