URI Component Encoder
Percent-encode or decode URI components and full URLs online.
About This Tool
The URI Component Encoder / Decoder wraps the browser's native encodeURIComponent, decodeURIComponent, encodeURI, and decodeURI functions in a convenient UI. Percent-encoding replaces characters that are not allowed in URLs with a % followed by two hexadecimal digits representing the UTF-8 byte.
encodeURIComponent / decodeURIComponent treats the input as a single component (query value, path segment), encoding all special characters. encodeURI / decodeURI treats the input as a full URL, preserving structural characters like ://?=# so the URL shape is maintained.
How to Use
- Choose Encode to percent-encode, or Decode to reverse the process.
- Select the function: encodeURIComponent for a single value, or encodeURI for a full URL.
- Paste your input or click Sample to load an example.
- Click Convert, then Copy the result.
Use Cases
Front-end developers encode query string values before appending them to URLs. Back-end engineers decode percent-encoded form payloads for inspection. QA engineers verify URL encoding before filing bugs. API integrators encode authentication tokens or special characters in request URLs.
FAQ
- What is the difference between encodeURI and encodeURIComponent? — encodeURI is for full URLs and does not encode characters valid at the URL level (:/?#&). encodeURIComponent is for individual components and encodes those structural characters too.
- Why does a space become %20 and not +? — Percent-encoding (%20) is the standard defined by RFC 3986. The + notation is specific to HTML form encoding (application/x-www-form-urlencoded) and is not used by these functions.
- Is my data sent anywhere? — No. Everything runs in the browser using JavaScript built-ins. Nothing is transmitted to a server.