Base64 Encoder & Decoder
Turn text into Base64 or read it back — Unicode-safe and never uploaded.
Encoding and decoding run on your device; nothing is uploaded.
01 Capability
What it does
Small details that make the job quicker.
- Encodes and decodes UTF-8 text, including emoji, accents and non-Latin scripts.
- Optional URL-safe alphabet, so the output can travel in a query string without escaping.
- Clear, human errors for bad characters, broken padding and bytes that are not text.
- Swap, sample, copy and clear are one press away, with a byte count on the result.
- Everything runs locally; the page makes no request with your data.
02 Questions
Questions
Short answers, no small print.
What is Base64, in plain words?
It is a way to write bytes using only letters, digits and a few symbols, so binary or Unicode text can travel through systems that expect plain ASCII. It is not encryption and it does not hide anything.
Why does my output end with one or two equals signs?
Those are padding. Base64 works in groups of four characters, and = fills the last group when the input length does not divide evenly. The decoder accepts input with or without the padding.
What does URL-safe change?
It replaces + with - and / with _, and removes the trailing padding. Those two characters have special meanings in URLs, so the URL-safe form avoids extra escaping.
Why can't it decode my Base64 file?
This tool decodes text. If the bytes are an image, a PDF or another binary file, they are not valid UTF-8 and the tool says so rather than showing broken characters.
Is the text sent to a server?
No. Encoding and decoding use the browser's own TextEncoder, TextDecoder and Base64 functions. Nothing is uploaded, and no copy is kept after you leave.