URLs have strict rules about which characters are allowed. Spaces, ampersands, equals signs, and non-ASCII text must be percent-encoded before they can appear in a URL. The Quill Tools URL Encoder/Decoder handles all of this instantly and for free.
Why URLs Need Encoding
RFC 3986 defines the URL syntax. Only a limited set of ASCII characters — letters, digits, and a few punctuation marks — are allowed "unreserved" in URLs. Everything else must be percent-encoded: represented as % followed by the two-digit hex code for the byte.
For example:
- Space →
%20 &→%26=→%3D+→%2B- 😀 (emoji) →
%F0%9F%98%80(UTF-8 encoded)
URL Encoding vs URL Component Encoding
There are two encoding functions with subtly different behaviour:
encodeURI()— Encodes a full URL. Leaves protocol (://), slash (/), and query delimiters (?,&,=) intact.encodeURIComponent()— Encodes a single component (query parameter value or path segment). Also encodes?,&,=and/. Use this for individual parameter values.
Quill Tools' encoder lets you choose between both modes.
Common Use Cases
- API query parameters — Encode search terms with special characters before appending them to a URL.
- Form data — HTML forms encode field values using
application/x-www-form-urlencoded, which is URL encoding. - OAuth redirects — Redirect URIs in OAuth flows must be percent-encoded.
- Debugging — Decode a messy encoded URL from logs or a browser address bar.
- Internationalised URLs — Non-ASCII characters in domain names (IDNs) and paths must be encoded.
How to Encode/Decode URLs with Quill Tools
- Open the URL Encoder / Decoder.
- Choose Encode or Decode mode.
- Paste your text or URL.
- The result appears instantly.
- Copy the output and use it in your application, API, or browser.
Frequently Asked Questions
What is URL encoding?
URL encoding replaces unsafe characters with percent-encoded equivalents so they can be safely transmitted in URLs.
When do I need URL encoding?
Whenever you include special characters in query parameters, form data, or API requests.
Encode or decode URLs for free at Quill Tools URL Encoder.