One input box and six operations: Base64 encode and decode, URL (percent) encode and decode, and HTML entity encode and decode. The page explains which problem each one solves: - Base64 lets binary data survive text-only channels, at about 33% extra size. - Percent-encoding keeps a + or & from splitting your query string. - HTML escaping on output is your first defence against XSS. It also states the thing people forget: Base64 is not encryption. It uses RFC 3986 encoding (a space becomes %20, not +). Free, with no sign-up, and nothing is stored. Made by Sanan as part of Web Tool Bench.