Base64 Encoder & Decoder
Encode text to Base64 or decode it back, live as you type — or encode a whole file. Base64 isn't encryption, just a way to represent binary data as plain text. Runs entirely in your browser; nothing here is sent anywhere.
Frequently asked questions
Is Base64 a form of encryption?
No — it's an encoding, not encryption. Anyone can decode Base64 back to the original data with no key or password required; it adds no confidentiality at all. Its actual job is making binary data safe to put somewhere that only expects plain text, like a JSON field, a URL, or an email attachment.
Why is the Base64 output longer than my input?
Every 3 bytes of input become 4 Base64 characters, so the output is roughly 33% larger than the original, plus a little more for padding. That overhead is the trade-off for representing arbitrary binary data using only printable, text-safe characters.
What's URL-safe Base64 for?
Standard Base64 uses + and /, both of which
have special meaning inside a URL or file path and would need to be
escaped. The URL-safe variant swaps them for - and
_ instead, so the result can be dropped directly into a
URL, filename, or cookie value without any extra escaping.
Is my file uploaded anywhere?
No. Files are read and encoded entirely on your device using the browser's built-in file APIs — nothing is sent to a server, which makes this safe to use on files you wouldn't want to upload to a random website.