Free online tools for encoding, decoding and working with common JavaScript and web data representations.
Use this guide to choose a suitable utility, understand the result and avoid common mistakes. The best workflow depends on your code, the intended output and where that output will be used.
Base64 and URL encoding change how data is represented so it can be transported or included in a particular context. They do not make the contents secret. Anyone with the encoded value can usually decode it without a key, so never treat encoding as a way to protect passwords, tokens or private data.
Use URL encoding for values placed in URL components, Base64 for data that needs a text-safe representation, and JavaScript string escaping when a value must be represented inside source code. These formats solve different problems and are not interchangeable. Applying the wrong decoder can produce garbled text or invalid output.
After decoding, inspect the output and confirm that it matches the expected text or bytes. If the result is binary data, a different character encoding is involved, or the input was truncated, a text decoder may not show a meaningful result. Preserve the original value before converting it.
Do not paste credentials, private keys, customer records or production secrets into a web tool unless you have verified how the page processes the input. Browser-side processing can reduce data transfer, but privacy claims should always match the actual implementation.