Query String Plus Sign Becomes Space – + vs %2B Explained

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Explain form-style query decoding where + represents a space while %2B represents a literal plus sign.

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Query string decoding behavior

Why does + become a space in a query string?

Query parameters parsed with URLSearchParams use form-style decoding. A raw plus sign represents a space, while the percent-encoded sequence %2B represents an actual plus character. This tool is free to use. No account or payment is required.

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What you can do here

  • Browser-native URLSearchParams behavior
  • Full URL and raw query parsing
  • Repeated parameter preservation
  • JSON object to query construction
  • Browser-local processing

Steps

  1. Paste the URL or raw query into Parse to JSON.
  2. Check whether the original value contains raw + or %2B.
  3. Use %2B when a literal plus sign must survive decoding.

Form-style query decoding is different from literal text

URLSearchParams follows application/x-www-form-urlencoded conventions for query data. That convention treats + as a space before percent-decoded values are exposed.

A literal plus is therefore represented as %2B. Encoding a space as %20 is also unambiguous when constructing URLs manually.

+ and %2B in the same query

The parser demonstrates the two meanings side by side.

Query string

?q=hello+world&literal=%2B

Parsed JSON

{
  "q": "hello world",
  "literal": "+"
}

Common questions

Frequently asked questions

Why does + mean space?

Query strings commonly use form-style URL encoding, where + is the compact representation of a space.

How do I send a literal plus sign?

Percent-encode it as %2B.

Does this affect the URL path too?

This page describes query parsing with URLSearchParams. Encode individual path or query components according to their own context.

Recommended next steps

Repeated Query ParametersSee how repeated keys become ordered JSON arrays instead of overwriting values.URL Encoder & Decoder OnlineEncode or decode one URL component when percent escapes are the issue.Query String Parser & Builder OnlineParse a URL or raw query into JSON, or build query parameters from JSON.

Debugging a specific Query String issue? Browse Query String troubleshooting.