URL Query Key Collision Audit

Audit query-name collisions after form-style percent decoding; encoded spellings and duplicate source positions remain visible.

Description

Audit query-name collisions after form-style percent decoding; encoded spellings and duplicate source positions remain visible.

Different raw query-key spellings can collide after plus and percent decoding. Occurrence indexes preserve that evidence.

When to use this tool

Audit query-name collisions after form-style percent decoding; encoded spellings and duplicate source positions remain visible.

Prepare the supplied query fields for this operation.
Compare the complete example with the representation used by your own input before carrying the result into another step.

How to use the tool and how it works

Enter query. Use the exact text syntax, units and index conventions explained below.
Run the tool. If input validation fails, correct the supplied fields before interpreting any result.
Read result.collisions. Interpret false, null and empty lists using the distinctions below; they can be valid outputs.

Parse nonempty ampersand pairs with strict form-style UTF-8 decoding, group exact decoded names and return repeated groups with their parsed pair indexes.^[1]

Input field	Meaning and representation	Accepted input
query	query.	Text; at most 8,192 UTF-16 code units, subject to the grammar above

Output field	Interpretation
result	Object containing the named outputs below.
result.collisions	The collisions list in the ordering and representation described above.

json

{
  "input": {
    "query": "a=1\u0026%61=2\u0026b=3"
  },
  "output": {
    "result": {
      "collisions": [
        {
          "name": "a",
          "indexes": [
            0,
            1
          ]
        }
      ]
    }
  }
}

Limitations and assumptions

Repeated identical raw spellings also count. Indexes exclude discarded empty fields; no case folding, Unicode normalization or parameter precedence is applied.
Every declared top-level field is required and unexpected fields are rejected. Numeric inputs must be finite; ordinary text fields are bounded to 8,192 UTF-16 code units, with tighter operation-specific limits where stated.
String lists have at most 128 entries of at most 128 code units; matrices have at most 128 rows and columns. Larger numeric lists and parsed JSON have separate bounded budgets. Nonfinite results and excessively large serialized outputs are rejected.
Indexes are zero-based and spans have an exclusive end unless explicitly stated otherwise. A valid false, null or empty-list result is distinct from malformed input.

Alternative or Complementary methods

Use a complete protocol or URL parser when interpreting a whole message or address. Preserve raw spelling when required and distinguish HTTP token grammar, URL path normalization and form-style query decoding.

References

Tool behavior and example: URL Query Key Collision Audit — tool.io

Similar or alternative tools

URL Query Key Repetition Summary
Summarize query-name repetition in first-seen order and retain all decoded values, including empty values.
url query count
A query is an ordered collection of name/value entries and may repeat a name.