Query String Parser / Builder

Encoding /query

Parse raw query strings into editable key/value rows and rebuild the query locally.

Transfer
Local only
Limit
5 MiB input
Paste with or without the leading ?. Rows update as you type.
Entries
Edit rows directly; the built query follows.
Parsed query entries will appear here.
Built query string
Built output will appear here.
0 rows ready. 1 line 33 B local only

How it works

Parse raw query strings into editable rows and rebuild them with repeated keys intact.

Use it to inspect repeated query parameters or rebuild them without manual escaping.

Example

Parse ?tag=json&tag=tools into two editable rows and rebuild the same repeated keys.

Notes

  • Repeated keys are preserved as separate rows.
  • Parsing catches malformed percent-encoded input.
  • Built output uses standard URL component encoding and starts with a leading ?.

Constraints

  • Works with query-string data and does not request or validate the target URL.
  • Limit: 5 MiB input. Nothing is uploaded or silently truncated.

Common errors

  • Malformed percent escapes
  • Confusing + with a literal plus
  • Oversized row data

When to use it

Use it to inspect repeated query parameters or rebuild them without manual escaping.

Formats: Leading ? optional, Repeated keys, Percent-encoded UTF-8.

Reference

WHATWG URLSearchParams

Substantively reviewed .