Decode from Base64 Format
Enter or paste your Base64 encoded string below to convert it back to readable text.
Decode File from Base64
Upload a text file containing Base64 data to decode it into original binary data (images, PDFs, documents, audio). Max 100MB.
About Base64 Decoding
Base64 is a binary-to-text encoding scheme defined in RFC 4648. It represents binary data in an ASCII string format by translating it into a radix-64 representation. It is widely used in email via MIME, data URIs in HTML/CSS, XML, JSON, and network protocols to safely transmit arbitrary byte sequences through channels designed only for text.
How Base64 Works
Every 3 bytes of raw binary data (24 bits) are divided into four 6-bit chunks. Each 6-bit group corresponds to an index (0 to 63) in the Base64 alphabet (A–Z, a–z, 0–9, +, /). When the input data is not an exact multiple of 3 bytes, padding characters (=) are appended to complete the 4-character block.
URL-Safe Base64
In standard Base64, the characters + and / have special meanings in URL parameters and filenames. The URL-safe variant (Base64URL) replaces + with - (hyphen) and / with _ (underscore), making it safe for query parameters and JSON Web Tokens (JWT).