swap_horizEncoding
Base64 Encoder / Decoder
A UTF-8 safe Base64 converter. Encode text or a whole file into a Base64 string, or paste a string back to recover the original. Supports the URL-safe alphabet used by JWTs and query parameters.
Base64UTF-8Data URI
input Plain text
output Base64
upload_file Encode a file
Pick a file to get its Base64 string and a ready-to-paste data URI. The file is read in your browser with the FileReader API — it is never uploaded.
What this tool does
- check_smallCorrect UTF-8 handling — emoji and accents survive the round trip
- check_smallStandard and URL-safe (base64url) alphabets
- check_smallDrop a file in to get a Base64 string or a ready-made data URI
- check_smallLive byte counts for the input and the output
Privacy
This tool runs entirely in your browser using client-side JavaScript. Whatever you paste stays on your machine — there is no back end, no upload and no analytics on your input.