Base64 Encoder & Decoder
Encode text to Base64 and decode Base64 to text instantly. Supports Base64, Base64URL, Base32, Base58, and Hex. 100% client-side — your data never leaves your browser.
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Base64 is a binary-to-text encoding scheme that represents binary data in an ASCII string format. It is commonly used when binary data needs to be stored or transferred over media designed to handle text. Base64 encoding is prevalent in web development for embedding images in HTML or CSS, encoding email attachments via MIME, transmitting binary data in JSON or XML, and storing complex data in cookies or URL parameters.
Our Base64 encoder and decoder runs entirely in your browser — no data is sent to any server. This means your sensitive API keys, tokens, and data remain private. The tool supports standard Base64 (RFC 4648), Base64URL (URL-safe variant used in JWTs), Base32, Base58 (used in Bitcoin addresses), and hexadecimal encoding.
Base64 works by taking groups of 3 bytes (24 bits) and splitting them into 4 groups of 6 bits. Each 6-bit group maps to one of 64 ASCII characters (A-Z, a-z, 0-9, +, /). If the input isn't divisible by 3, padding characters (=) are added. This is why Base64-encoded data is always roughly 33% larger than the original.
Base64URL is a variant that replaces + with - and / with _, making it safe for use in URLs and filenames. It's the encoding used in JSON Web Tokens (JWTs) and many modern APIs.
Whether you're debugging API responses, decoding JWT tokens, or embedding images in your code, this tool gives you instant, private, and accurate results.
Frequently Asked Questions
Base64 is a binary-to-text encoding scheme that represents binary data using 64 ASCII characters (A-Z, a-z, 0-9, +, /). It is commonly used to embed binary data in text-based formats like HTML, CSS, JSON, and email.
No. Base64 is an encoding format, not encryption. It provides no security — anyone can decode Base64 data without a key. For actual data protection, use encryption algorithms like AES or RSA.
Base64 encodes every 3 bytes of input into 4 ASCII characters. This 3-to-4 ratio means the output is always approximately 33% larger than the input. Padding characters (=) may add a few extra bytes.
Use Base64 when you need to transmit binary data over text-only channels — for example, embedding images in HTML/CSS, encoding email attachments (MIME), passing binary data in JSON or XML, or storing data in cookies and URL parameters.