UTM Builder
A UTM builder is a tool that appends tracking parameters to a landing page URL. It takes the base URL, keeps…
Free URL encoder and decoder
Percent encode or decode URLs and query strings, with every parameter shown in plain text.
Result
| Parameter | Decoded value |
|---|
The free url encoder decoder runs in your browser, needs no sign-up and never sends what you type anywhere.
Quick answer
This URL encoder decoder converts unsafe characters into percent codes such as %20 for a space and %C3%BC for u with umlaut, or turns them back into readable text. Rule of thumb: encode each query parameter value separately, and encode a full URL only once, because double encoding turns %20 into %2520.
What is a URL encoder decoder?
A URL encoder decoder is a tool that applies percent encoding, where each byte of a character's UTF-8 form is written as % followed by two hex digits. Component mode escapes reserved characters like ? & = / #, while full URL mode keeps them so the address still works.
How do you use the URL Encoder Decoder?
- Paste text, a query value or a full URL into the input box.
- Choose Encode value, Encode full URL or Decode.
- Tick Spaces as + if you are building form style query strings.
- Copy the result and paste it into your link, redirect rule or tracking URL.
- Check the parameter table to confirm each decoded value is correct.
What is %20 in a URL?
%20 is the percent encoded form of a space character, because spaces are not allowed in URLs. In HTML form data, spaces may also be written as +. MDN's percent encoding glossary lists the reserved characters and their codes.
Should URLs with non-English characters be encoded?
Yes, in links and HTTP requests non-ASCII characters should be percent encoded as UTF-8 bytes, and browsers do this for you when you type them. Google's URL structure guidance shows examples such as gem%C3%BCse and recommends readable words in URLs, so the visible form can still be friendly.
What is the difference between encodeURI and encodeURIComponent?
encodeURI keeps characters that structure a URL, such as : / ? # & and =, so it is meant for a whole address. encodeURIComponent also escapes those characters, so it is meant for a single value inside a query string or path segment.
Quick reference
| Character | Encoded | Where it matters |
|---|---|---|
| Space | %20 (or + in forms) | Any part of a URL |
| & | %26 | Inside query values |
| = | %3D | Inside query values |
| ? | %3F | Inside paths and values |
| # | %23 | Anywhere not meant as a fragment |
| u with umlaut | %C3%BC | Non-ASCII text in URLs |
Worked example
Example
Example: a UTM campaign name "spring sale & offers" encoded as a value becomes spring%20sale%20%26%20offers, so the & no longer splits the query. Decoding https://example.com/?q=caf%C3%A9%20menu returns the parameter q with the value "café menu".
Frequently asked questions
What is double encoding?
Double encoding happens when already encoded text is encoded again, so % becomes %25 and %20 turns into %2520. It breaks links and tracking. If you see %25 in a URL, decode it once and check whether the original was already encoded.
Why does decoding fail with an error?
Decoding fails when a % sign is not followed by two valid hex digits, or when the bytes do not form valid UTF-8. The tool shows a friendly message instead of crashing. Encode a literal percent sign as %25.
Should I use + or %20 for spaces?
Use %20 in paths and in most URLs. The + form is a convention for application/x-www-form-urlencoded data, mainly query strings from HTML forms. Many servers accept both in query strings, but only %20 is safe in a path.
Does URL encoding affect SEO?
Encoding itself does not hurt rankings, and Google handles percent encoded URLs. Problems come from inconsistent versions of the same URL, such as encoded and unencoded forms both being linked. Pick one form, link to it consistently and set a canonical.
Which characters never need encoding?
Letters A to Z and a to z, digits 0 to 9, and the characters hyphen, period, underscore and tilde are unreserved and never need encoding. Using hyphens between words keeps URLs readable for people and search engines.
Is anything I paste sent online?
No. Encoding and decoding use the browser's built in functions, and nothing is sent to a server or stored. You can safely decode URLs that contain tracking IDs or tokens, but avoid sharing those URLs publicly.
Sources
Facts checked against these official pages. Read how I check facts in my editorial policy.
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