Web guide
How to use a query string parser
A query string parser turns the parameter portion of a URL into readable name and value rows, making encoded text, repeated parameters, and empty values easier to inspect.
Open the Query String ParserParse and rebuild a query
- Paste a full URL or a query beginning with
?. - Select Parse query.
- Review the decoded name and value for every row.
- Edit, add, or remove rows as needed.
- Select Rebuild query and copy the encoded result.
The ToolPixels output is the query only, without a leading question mark. Add ? when attaching it to a URL.
Worked example
?name=Alex&tag=one&tag=two
| Row | Name | Value |
|---|---|---|
| 1 | name | Alex |
| 2 | tag | one |
| 3 | tag | two |
The repeated tag name is not an error. Many systems use repeated parameters for lists, so the parser preserves both rows and their order.
Encoding rules that matter
- A plus sign normally decodes to a space in query data.
- Use
%2Bwhen the value must contain a literal plus sign. - Use
%23for a literal#; an unescaped hash begins the fragment. - A bare flag such as
?previewis rebuilt aspreview=. - Percent escapes are decoded once as UTF-8.
- Invalid percent escapes should be corrected rather than silently guessed.
Empty values and missing parameters
?q= contains one parameter named q with an empty value. A lone ? contains an empty query. Those cases can have different meaning to an application, so avoid deleting empty rows unless you understand how the receiving system treats them.
Also distinguish a missing parameter from the text null, false, or 0. Query strings carry text; the application decides how to interpret it.
Use the parser safely
Review links before sharing them because query values may contain search terms, email addresses, campaign data, or access tokens. The free query string parser processes input locally, but the rebuilt URL may still expose its query anywhere you later paste or visit it.