tool4.dev

Encoding / LOCAL TOOL

URL Encoder & Decoder

Encode or decode URL components locally without exposing query data to the server.

Runs locally — input is never uploaded
Paste text or a URL component
Ready when you are

WHAT IT DOES

Percent-encoding that matches what your code will do.

Encode a value for safe use inside a query string or path segment, or decode a percent-encoded string back to readable text. The tool uses the browser's own encodeURIComponent and decodeURIComponent, so the output matches what JavaScript, and by extension most HTTP clients, will produce.

Why use it?

Use component encoding when a value contains characters that would otherwise become URL separators—for example, an ampersand inside a search term.

How to use this tool

  1. Paste a single query value or path component and encode or decode it.
  2. For example, red & blue encodes to red%20%26%20blue. Do not encode a whole URL as one component unless you intend to embed that URL inside another value.
  3. Check for double encoding: %20 encoded again becomes %2520. Decode leaves a literal + unchanged; form-style query inspection belongs in URL Inspector.

Details and limitations

  • Component encoding escapes the reserved characters &, =, ?, #, /, and space, which is what query parameter values need.
  • Decoding reports malformed percent sequences instead of throwing away the input.
  • Plus signs are treated as literal characters, not as spaces; form encoding is a different scheme.
  • Non-ASCII text is encoded as UTF-8 percent sequences.

WORKED EXAMPLES

Keep an ampersand inside a query value

Encode the phrase below as one component, then insert the result after q= in your URL. Encoding the entire URL would also escape its structural separators.

Query value

red & blue

Expected result

red%20%26%20blue. The encoded ampersand belongs to the value rather than starting another query parameter. Encoding this output again would change % into %25.

COMMON QUESTIONS

URL Encoder questions

What is the difference between encoding a URL and a URL component?
Component encoding escapes reserved characters such as & and =, which is correct for a single parameter value. Encoding a whole URL must leave those characters intact so the URL still parses. This tool encodes components.
Why does a space become %20 and not a plus sign?
%20 is the correct percent-encoding for a space. The plus sign only means a space in application/x-www-form-urlencoded form bodies, which is a separate encoding.
Does it handle non-English characters?
Yes. Characters outside ASCII are encoded as UTF-8 byte sequences, which is what modern servers and frameworks expect.