URL Encoder & Decoder

When checked, the tool uses encodeURIComponent/decodeURIComponent, which escapes nearly every special character — the right choice for a single query value like a search term. When unchecked, it uses encodeURI/decodeURI, which leaves characters like :, /, ?, and & untouched because they're structurally meaningful in a full URL.

encodeURIComponent escapes "/" and "?" along with everything else, so running a complete URL like https://example.com/path?q=1 through it would mangle the scheme and path. Uncheck the box first if you're encoding a full URL rather than a single value.

It converts the space to its percent-encoded form, %20, following standard percent-encoding rules; other special characters like &, =, and # are similarly converted to their %XX hex equivalents.

decodeURIComponent and decodeURI throw an error on malformed percent sequences, such as a stray "%" not followed by two valid hex digits. The tool catches that and tells you the input may contain invalid encoding. In batch mode, only the specific line with the problem is marked as invalid in the result — the rest of the batch still processes normally.

When "Batch mode" is checked, the tool treats each line of the input as a separate item and encodes or decodes them independently, joining the results back together one per line — useful for processing a list of URLs or query values at once. If one line contains invalid encoding, only that line is marked as unable to process; the rest of the batch still completes.

%20 is the standard percent-encoding for a space and is what encodeURIComponent and encodeURI produce. The + character is a separate, older convention used specifically by the application/x-www-form-urlencoded format (classic HTML form submissions and query strings built that way) to represent a space. Checking "Use + for spaces" makes the tool convert between + and a literal space instead of %20, matching that form-encoded convention.

The Live Preview updates as you type and highlights, character by character, exactly which parts of your input will change. In Encode mode it highlights characters that aren't safe to leave as-is and shows what they become; in Decode mode it highlights each %XX sequence (and + if that option is checked) and shows what it decodes to, so you can see exactly why the output looks the way it does before running the conversion.

No — encoding and decoding are done entirely with the browser's built-in encodeURIComponent, decodeURIComponent, encodeURI, and decodeURI functions, running locally on your device.