What is URL encoding?
URL encoding represents characters as percent-encoded bytes. Each byte is written as % followed by two hexadecimal digits. It lets text values fit into a URL without their characters being mistaken for URL structure.
Percent encoding is different from Base64 encoding. Base64URL is a Base64 variant, not URL percent encoding.
Encode an individual URL component
Use URL component mode for individual values such as search terms, query parameter values or path segments. For example, hello world becomes hello%20world.
Characters such as &, ?, # and / can have structural meaning within URLs. Do not encode an entire URL as one component when you want to preserve that structure.
Work with a complete URL
Complete URL mode requires an explicit absolute HTTP/HTTPS URL. It preserves URL structure while using native URL parsing and serialisation. Native URL normalisation can change the displayed spelling, including hostnames, default ports and dot segments. Exact textual round trips are not guaranteed.
The complete-URL decoder conservatively preserves encoded delimiters where decoding would change interpretation. It does not decode every reserved character into literal text or repair malformed URLs.
Form and query values: %20 versus +
Form/query-value mode follows application/x-www-form-urlencoded value conventions. It uses + for spaces and encodes a literal + as %2B. For example, hello world becomes hello+world.
Normal URL component encoding uses %20 for spaces. A + does not automatically mean a space in normal URL component decoding. Select the mode that matches the source of your value.
Unicode and invalid encoded text
UTF-8 percent encoding supports accented text, non-Latin scripts and emoji. A character can require several encoded bytes.
Malformed percent escapes or invalid UTF-8 can produce validation errors. Check the input and selected mode before trying again. The utility does not automatically repair malformed URLs.
Your text stays in your browser
Text and URLs are encoded or decoded in your browser and are not sent to UtiliBits. The utility does not fetch or automatically follow entered URLs, or store your input and output.
Frequently asked questions
What is URL encoding?
URL encoding represents characters as percent-encoded bytes so they can be used in a URL. Encode individual values with URL component mode, or use Complete URL mode to preserve the structure of an absolute HTTP/HTTPS URL.
What is the difference between encoding a URL and a URL component?
Component mode encodes individual search terms, query parameter values or path segments. Complete URL mode requires an explicit absolute HTTP/HTTPS URL and preserves its structure through native URL parsing and serialisation. Native normalisation can change the displayed spelling, so exact textual round trips are not guaranteed.
Why are spaces encoded as %20 or +?
URL component encoding uses %20 for a space. Form/query-value encoding follows application/x-www-form-urlencoded value conventions: it uses + for spaces and %2B for a literal +. A + does not automatically mean a space in normal URL component decoding.
Does the converter support Unicode and emoji?
Yes. UTF-8 percent encoding supports accented text, non-Latin scripts and emoji. Invalid UTF-8 can produce a validation error when decoding.
What is percent encoding?
Percent encoding writes a byte as % followed by two hexadecimal digits. For example, a space becomes %20. UTF-8 characters can require several percent-encoded bytes.
Can I decode an entire URL?
Yes, with Complete URL mode and an explicit absolute HTTP/HTTPS URL. The decoder conservatively preserves encoded delimiters where decoding would change interpretation. Characters such as &, ?, # and / can have structural meaning. Native URL normalisation applies, and the tool does not repair malformed URLs.
What happens if encoded text is invalid?
Malformed percent escapes or invalid UTF-8 can produce validation errors. Check the input and selected mode, then correct the value. The utility does not automatically repair malformed URLs.
Are my URLs sent to UtiliBits?
No. Text and URLs are encoded or decoded in your browser and are not sent to UtiliBits. The utility does not fetch or automatically follow entered URLs, or store your input and output.