Free Online Base64 Encoder/Decoder

Base64 is a way of representing binary data (or any text) using only 64 printable ASCII characters (A–Z, a–z, 0–9, +, /). It's used whenever data needs to pass through a system that only reliably handles text — like embedding an image inside HTML/CSS, attaching files to an email, or including binary data in a JSON payload.

No. Base64 is encoding, not encryption — it provides zero security. Anyone can decode Base64 text back to its original form instantly with no key or password required. Never use Base64 alone to "hide" passwords, tokens, or sensitive data; use real encryption (like AES) or hashing if you need security.

Yes. This tool UTF-8 encodes your text before Base64-encoding it, so it correctly handles emoji, Chinese, Japanese, Korean, and any other Unicode text. The plain browser btoa() function only supports Latin1 characters and throws an error on anything outside that range — this tool avoids that limitation entirely.

Yes. All encoding and decoding happens entirely inside your browser using JavaScript. Nothing you type is uploaded, logged, or sent to a server. You can disconnect from the internet after the page loads and it will keep working.

Common uses include embedding images directly in HTML or CSS as data URIs (data:image/png;base64,...), attaching files to emails via MIME encoding, encoding the header and payload segments of JWT authentication tokens, and embedding binary data inside JSON or XML documents that only support text.

Standard Base64 uses + and / characters, which have special meaning in URLs and file paths. URL-safe Base64 (used in JWTs and many web APIs) replaces + with -, / with _, and often drops the trailing = padding, so the result can be used directly inside a URL or filename without extra escaping.