Query String Parser and Builder
Paste a full URL or raw query string to decode query parameters, edit key-value pairs, convert query strings to JSON, rebuild encoded URLs, and debug API request parameters directly in your browser.
The Query String Parser and Builder helps developers, students, API testers, WordPress users, and support teams understand what is inside a URL after the question mark. A query string can contain search terms, filters, UTM campaign tags, pagination values, API keys, sorting options, tracking IDs, and encoded JSON values. This tool extracts those parameters into an editable table so you can inspect, change, rebuild, and copy the result.
This tool works naturally with the CodeZips URL Encoder and Decoder. Use the URL Encoder when you need to encode or decode one value, and use this Query String Parser when you need to understand a full set of URL parameters. If a query parameter contains JSON, you can paste the decoded value into a JSON formatter. If a parameter contains a token, inspect it carefully and avoid sharing private keys, access tokens, or session identifiers.
Parse, Edit and Rebuild a Query String
Input
Output
Related URL and API Tools
Query strings are only one part of URL debugging. When one parameter is encoded incorrectly, the whole request can fail or return a different result than expected. For single-value encoding, use the URL Encoder and Decoder. For API payloads, JSON utilities are useful when a query value contains encoded JSON. For tokens inside URLs, decode only safe sample tokens and never expose real secrets.
Encode or decode individual URL values, full URLs, path segments, and query parameter values.
A good next tool for removing UTM, gclid, fbclid, and tracking parameters from copied links.
A natural follow-up for developers who need to convert API filter objects into URL parameters.
What Is a Query String?
A query string is the part of a URL that comes after the question mark. In a URL like https://example.com/search?q=php&page=2, the query string is q=php&page=2. Each parameter usually has a key and a value. The key describes the setting, and the value stores the selected data.
Query strings are common in search pages, filters, analytics links, API requests, checkout links, documentation URLs, and web app routes. A search page may use q=javascript. A product page may use sort=price. An API may use limit=20&offset=40. A campaign URL may include utm_source, utm_medium, and utm_campaign.
Worked Examples
| Input | What it means | Common use |
|---|---|---|
| ?q=url%20tools&page=2 | The search term is “url tools” and the page number is 2. | Search results and pagination. |
| utm_source=google&utm_medium=cpc | The traffic source is Google and the medium is paid search. | Marketing campaign tracking. |
| tag=php&tag=api&tag=json | The same key appears multiple times with different values. | Filters, tags, checkboxes, and multi-select values. |
| redirect=https%3A%2F%2Fcodezips.com%2Furl-encoder-decoder%2F | The value is another encoded URL. | Redirect links, login callbacks, and return URLs. |
Common Query String Mistakes
Using a full URL as a query value without encoding it. If a query parameter contains another URL, the inner URL should be encoded. Otherwise, characters like ?, &, and = may be treated as part of the outer URL instead of the value.
Forgetting that plus signs can mean spaces. In many form-style query strings, + represents a space. That is why this tool includes an option to treat plus signs as spaces when decoding. But not every plus sign should be treated that way in every context, especially when working with strict encoded values.
Losing duplicate parameters. Some parsers convert duplicate keys into only one value. For example, tag=php&tag=api may become only the last value if the parser is too simple. This tool preserves duplicate keys and shows them as arrays in the JSON output.
Mixing path encoding with query value encoding. A query value and a URL path segment are not always encoded for the same purpose. When you only need to encode a single value, use the URL Encoder and Decoder first so you can clearly see what changed.
When Developers Use a Query String Parser
Developers use query string parsers when debugging APIs, copying links from logs, testing search filters, comparing UTM campaigns, checking redirect URLs, or trying to understand why a request returns the wrong data. A query string parser is also useful for students learning HTTP requests because it shows how a URL stores structured information in a simple text format.
For API work, this tool is useful when a request has many filters. Instead of reading a long URL manually, you can paste it into the parser and see each parameter in its own row. Then you can edit one value, rebuild the query string, and test the updated URL in your browser, API client, or documentation page.
Frequently Asked Questions
What is a query string parser?
A query string parser extracts URL parameters from a full URL or raw query string and displays them as readable key-value pairs. It helps you decode, edit, inspect, and rebuild URL parameters.
Can this tool convert query strings to JSON?
Yes. After parsing a query string, the tool creates a JSON object. Duplicate keys are converted into arrays so repeated parameters are not lost.
Can I build a query string manually?
Yes. Click Add Parameter, enter keys and values, then click Build Query. The tool encodes the values and generates both a query string and a full URL if you provide a base URL.
Does this tool handle UTM parameters?
Yes. You can parse and inspect UTM links that include parameters like utm_source, utm_medium, utm_campaign, utm_term, and utm_content.
Is this query string parser safe for private URLs?
The parsing happens in your browser, but you should still avoid pasting private tokens, API keys, session IDs, signed URLs, or confidential customer information into online tools.
