Is Base64 encoding safe for secrets?

No. It is reversible with no key and no effort — it exists to move bytes through text-only pipes, not to hide them. Encrypt before encoding if the content is sensitive.

Why do the = signs appear at the end?

Padding. Base64 processes three bytes at a time into four characters, so a final group of one or two bytes gets one or two '=' to keep the total length a multiple of four.

What is the difference from Base64URL?

Base64URL swaps '+' for '-' and '/' for '_' and usually drops the padding, so the string survives being put in a URL or a filename. They are otherwise the same alphabet.

Does encoding make files bigger?

Yes, by about a third. That is the cost of squeezing 8-bit bytes into 64 safe characters, and it is worth budgeting for when you inline an image as a data URI.

Text & Data Ready to use

Base64 Encoder

Turn text into Base64 with correct UTF-8 or Latin-1 byte handling, and see the exact byte count, output length and size overhead before you paste it anywhere.

Input

Operation

Character set

This tool runs entirely in your browser. Your input never leaves your device.

About Base64 Encoder

Base64 rewrites binary data using 64 printable characters, so bytes can travel through channels that were only ever built for text — an email body, a query string, a JSON field, the inside of a data: URI. It is an encoding, not encryption: anyone can decode it in a second, and it has no business protecting anything.

The part that goes wrong in practice is character encoding. This encoder takes your input as UTF-8 by default, so an é, an emoji or a non-Latin script becomes the correct multi-byte sequence and comes back intact on the other side. Switch to Latin-1 when you are matching a legacy system that really does treat each byte as ISO-8859-1; if a character above U+00FF turns up in that mode, the tool names it and its position instead of silently corrupting it.

Output length is always a multiple of four, which is why '=' padding appears: three input bytes become four characters, and a leftover byte or two are padded out. The overhead is roughly 33%, and the result panel shows the real numbers for your input so you can judge whether a header or a payload limit will take it.