Base64 / Hex / Binary

Two-way encode and decode text across Base64, URL, hex and binary. Free, runs entirely in your browser — no signup, and nothing you paste in is uploaded.

Base64 exists because a lot of the internet was built to carry text, not bytes. It maps every three bytes onto four characters from a 64-symbol alphabet, which is why encoded output is always about a third larger than what went in, and why the length is always a multiple of four once padding is added.

It is not encryption and never has been. Anything Base64 can hide, any reader can reveal in a second — the reason it turns up in tokens, data URIs and email attachments is transport safety, not secrecy. The URL-safe variant swaps `+` and `/` for `-` and `_` so an encoded value survives being pasted into a query string.

Hex and binary are for a different question. Base64 tells you a payload travelled intact; hex shows you the actual bytes, which is what you want when a file has the wrong magic number or a string has a byte-order mark nobody expected.