You paste text and choose Encode or Decode. In encode mode, the tool converts UTF-8 text into bytes, groups them into 6-bit chunks, and maps each chunk to a character in the Base64 alphabet (A–Z, a–z, 0–9, +, /). In decode mode, it reverses the process. Everything runs in your browser — no data is sent to a server.
No. Base64 is an encoding scheme, not encryption. Anyone can decode a Base64 string without a key. It is used to safely transmit binary data over text-based channels, not to keep data secret.
Base64 represents every 3 input bytes as 4 output characters, producing roughly 33% overhead. Padding characters (=) may also be added to bring the output length to a multiple of 4.
This tool handles text input only. To Base64-encode a file, you would need to read it as raw bytes first. Many programming languages and CLI tools (like the base64 command on macOS/Linux) support file encoding directly.
The input string contains characters outside the Base64 alphabet or has incorrect padding. Valid Base64 uses only A–Z, a–z, 0–9, +, /, and = for padding. Check for accidental spaces or line breaks.
Estimate only. Results reflect your inputs and standard formulas. Double-check important decisions independently.