About URL encoding and decoding
Overview
URL encoding converts special characters so they can be safely used in query strings and paths. Reserved characters such as spaces, ampersands, equals signs, and non-ASCII letters must be represented in a way that does not break the URL structure. Our tool supports both standard percent-encoding (RFC 3986) and query string mode where spaces become plus signs, as in application/x-www-form-urlencoded data.
Encoding is essential when building links that include user input, API parameters, or dynamic path segments. Decoding is needed when you receive or parse URLs and need to display or process the original values.
When to use it
Use encoding when constructing URLs with dynamic parts: search query parameters, redirect URLs, file names in paths, or any string that may contain spaces or special characters. Use decoding when reading query parameters from a URL, parsing links from HTML, or debugging encoded strings. Combine with the Sitemap Generator when your sitemap contains URLs with special characters; use the SEO Analyzer to verify that encoded links are correct on your pages.
How to use it
Paste your text into the input area. Click Encode to convert special characters to percent-encoded form (e.g. space to %20). Click Decode to convert percent-encoded sequences back to readable text. Enable "Query string mode" if you need spaces as + and plus signs decoded as space, which matches form submission behavior. Use the Swap button to move the output back to the input for another round of encoding or decoding. Copy the result into your application or URL bar as needed.
Tips & best practices
Always encode user input before putting it in URLs to avoid injection or broken links. Do not double-encode: encoding an already encoded string will turn % into %25 and break decoding. For query parameters, use query string mode when your backend or API expects application/x-www-form-urlencoded format. When in doubt, encode; most servers and clients handle encoded URLs correctly. For crawl and SEO checks, use Robots.txt and the SEO Analyzer to ensure your site structure and links are valid.
Common mistakes
Double encoding happens when you encode a string that is already encoded; the decoder will show a warning if it detects malformed percent-sequences (a % not followed by two hex digits). Mixing encoding modes can cause issues: for example, using + for space in a path instead of %20 may not be interpreted correctly by all servers. Another mistake is decoding without checking: if the source is not actually encoded, decoding may leave percent signs or produce wrong characters. Always verify the context (path vs query string) and use the matching mode in the tool.