Base64 Encode / Decode

Base64 is everywhere in software: API keys and Basic Auth headers, email attachments, data URLs embedding images in CSS, JWT segments, configuration files. It's an encoding — not encryption — that represents any data using 64 safe characters, so binary or special-character content can travel through systems that only handle plain text. Developers constantly need to peek inside a Base64 string or produce one, and this tool does both directions live as you type.

The detail that separates this converter from naive ones: full UTF-8 support. The browser's built-in btoa/atob functions choke on anything outside Latin-1 — encode an emoji or Hindi text with a naive tool and you get an error or corrupted output. This tool routes text through proper UTF-8 encoding first, so "नमस्ते 👋" round-trips perfectly.

The Swap button feeds your result back in as new input with the direction flipped — a one-click round-trip check to confirm an encode/decode pair is lossless. Everything runs locally: paste tokens, credentials in transit, or API payloads knowing they never leave your machine, which is precisely what you want when the string you're decoding is an authorization header.