About encodeURIComponent Online
This tool encodes text with the same rules as the JavaScript function encodeURIComponent. It starts in Component mode, so every character that has a meaning in a URL is encoded. It is free, needs no sign-up and runs in your browser, so nothing you enter is uploaded.
encodeURIComponent leaves these characters alone: letters A to Z and a to z, digits 0 to 9, and - _ . ! ~ * ' ( ). Everything else becomes UTF-8 bytes written as %XX. That means / ? # & = + , ; : @ $ and the space are all encoded, which is what you want for one value and wrong for a whole URL.
The common bug is in building a URL by hand. Write the value through encodeURIComponent and then add it: "https://example.com/search?q=" + encodeURIComponent(term). Writing "?q=" + term breaks the moment term contains an ampersand, a hash or a plus sign. Pasting a sample value here shows what the function will return, with no need to open a console.
Note that encodeURIComponent does not encode the characters ! * ' ( ), which are legal in a URL but are sometimes troublesome inside a query value, for example in a signed request. Some code replaces them by hand afterwards. Also, the function throws a URIError for a lone surrogate half of an emoji. This page matches the browser function, so it will not hide that behaviour.
How to use encodeURIComponent Online
- Choose Encode to percent-encode text, or Decode to turn an encoded string back into text.
- Paste your text or URL into the box. The result appears as you type.
- When encoding, choose Component (encodeURIComponent) for one value, or Full URL (encodeURI) for a whole address that should keep its slashes, question mark and ampersands.
- Tick Space as + if the value goes into an HTML form style query string. When decoding, tick + means space for the same kind of data.
- Read the Query parameters table to see each key and value of a URL decoded.
- Use Show percent-encoding chart to look up the code for a character, then Copy to take the result.
Features
- Encode and decode in one tool, with the result updating as you type.
- Two encoding modes: Component (encodeURIComponent) and Full URL (encodeURI).
- UTF-8 aware, so accented letters, Bangla, Chinese and emoji become the correct multi-byte percent sequences.
- Space as %20 or as +, for forms and for URLs.
- Decode with the option + means space.
- A clear error, Input contains an invalid percent sequence, when something like %G1 or a stray % is found.
- Query parameters table that decodes every key and value of a URL or a bare query string.
- Percent-encoding chart of common special characters, with the reserved ones marked.
- One-click copy of the result.
Worked examples
a=1&b=2 gives a%3D1%26b%3D2
https://example.com/?q=1 gives https%3A%2F%2Fexample.com%2F%3Fq%3D1
Encoded as one value, so it can be safely put in a redirect parameter.
it's (fine)! gives it's%20(fine)!
The apostrophe, parentheses and exclamation mark are not encoded by encodeURIComponent.
€ and 😀 gives %E2%82%AC%20and%20%F0%9F%98%80
Privacy: how it works
- The text and URLs you enter are processed by code in your browser tab. Nothing is sent to Ulkaa or to any other server, which you can confirm in the Network tab of your browser developer tools.
- That is useful because real URLs often carry tokens, email addresses and session identifiers in their query strings. You can inspect and decode them here without sending them anywhere.
Tips
- Decode a URL from a log or an email to see what a tracking link really contains. The Query parameters table lists each key and value.
- Encode the value, not the whole URL, when you build a link by hand with a parameter such as ?next=.
- If decoding fails, look for a bare % that was not meant as an escape, for example in 100% or in a copied sentence. Encode it as %25 first.
- Reserved characters are only a problem inside a value. In their normal place, a ? that starts the query or a & that separates parameters, they must stay as they are.
Frequently asked questions
Is it really free?
Yes. There is no price, no trial and no credit card. Ulkaa Tool does the work with your own device, so there is no server bill to pass on to you.
Do I need an account?
No. There is no sign-up and no login. Open the page and use it. An Ulkaa account is not needed for anything on this tool.
Does it run in my browser?
Yes. Your text and URLs are processed by code running in your browser tab, on your own device.
Is my data uploaded?
No. Your text and URLs are never sent to Ulkaa or to anyone else. You can check this yourself by watching the Network tab in your browser developer tools while you use the tool.
What is the difference between encodeURI and encodeURIComponent?
encodeURI keeps characters that have meaning in a URL, such as / ? & = and #. encodeURIComponent encodes them too, so it is meant for a single value. Both leave letters, digits and - _ . ! ~ * ' ( ) alone.
Does encodeURIComponent encode a space as + or %20?
It uses %20. If you need a plus sign for form-style data, tick Space as + here, or replace %20 with + in your code.
Does encodeURIComponent encode the apostrophe and parentheses?
No. The characters ! * ' ( ) are left as they are. If an API needs them encoded, replace them yourself with %21, %2A, %27, %28 and %29.
More URL Encoder and Decoder pages
- URL Encoder and DecoderPercent-encode text so it is safe in a URL, or decode an encoded URL back to readable text.
- URL Encoder OnlinePercent-encode a URL or a piece of text so it works as a link.
- URL Decoder OnlineTurn %20, %C3%A9 and other percent codes back into readable text.
- Percent-Encoding ChartLook up the %XX code of a special character and see which characters are reserved in URLs.