Use the free Query String to JSON Converter below: your data never leaves your browser — all work happens on your device, and nothing is uploaded to any server.
What this tool does
Every link with a question mark carries hidden data. The part after the ? in a URL is the query string: a list of parameters like name=Ana and city=Madrid, joined by & signs. Web apps, tracking links, search pages, and APIs all use query strings to pass information from one page to another. But a query string is hard to read when it is long, encoded, or full of repeated parameters. The Query String to JSON Converter turns it into clean, readable JSON, so you can see exactly what a link carries.
JSON is easier to read than a query string for three reasons. Keys and values are separated clearly, repeated parameters become visible as arrays, and encoded characters are decoded back into normal text. A query string like tag=news and tag=sports becomes a JSON array with two items, which shows at a glance that two tags were passed. That clarity is the whole point of the tool.
How to parse a query string
Paste the query string into the input box, with or without the leading question mark. Both forms work. You can paste just the parameters, or the full query part of a URL. Press Convert, and the output box shows a JSON object with one key per parameter, formatted with indentation. Press Copy output to copy it, or Download JSON to save it.
Repeated parameters become arrays automatically. If a link passes tag twice, the JSON shows tag as an array of both values, in order. Encoded characters are decoded for you: %20 becomes a space, %2F becomes a slash, and accented characters return to normal letters. The message under the output tells you how many parameters were parsed, which is a quick check that nothing was lost.
Where query strings appear
Query strings are everywhere on the web. Search pages put your search terms in the query string. Shopping sites put filters, sort order, and page numbers there. Tracking links add campaign names and source labels. APIs accept options as query parameters, such as a limit, a language, or a category. Social share links carry the shared page address as a parameter. When something about a link looks wrong, the query string is usually the first place to look.
Developers debug query strings daily: a missing parameter explains a blank page, a wrong value explains a wrong result, and a duplicated parameter explains a filter that behaves strangely. Analysts inspect tracking links to confirm campaigns are tagged correctly. Support staff decode a customer’s link to see what the customer actually clicked. In each case, JSON makes the inspection faster than staring at a long, encoded string.
Tips for reading query strings
First, look for parameters you did not expect. Tracking links often carry more parameters than the visible page suggests, including campaign, medium, and source labels. Second, check repeated parameters carefully. A parameter that appears twice may be intentional, as with multiple tags, or it may be a bug, as with a filter applied twice. The JSON array makes repeats obvious.
Third, remember that query string values are always text. A value like “5” is the text “5”, not the number 5, and a value like “true” is the text “true”. If you feed the JSON into code, convert types explicitly. Fourth, be careful with sensitive data. Query strings appear in browser history, server logs, and shared links, so passwords and tokens should never travel as query parameters. If you find one in a link you are inspecting, treat it as a security issue, not just a curiosity.
Privacy and limits
Your query string never leaves your browser. Parsing runs on your device with the browser’s own URLSearchParams, and nothing is uploaded. That matters because links can contain personal data: search terms, account identifiers, and session details. You can inspect a link safely here, without sending it to a server.
The tool parses standard query strings, with & between parameters and = between key and value. It does not fetch the URL or follow the link, so it cannot tell you what the page does with the parameters. It also does not decode parameters that are themselves encoded JSON or encoded URLs a second time; if a value looks like encoded text after the first decode, decode it once more by hand, or paste it into the tool again.
Finally, verify the result before acting on it. Count the parameters, check the values that matter, and compare them with what the page shows. A quick check turns a confusing link into a clear list of facts, and it catches the missing parameter before it becomes a support ticket.
Related tools
- Convertir Query String a JSON Gratis (Spanish version)
- JSON to Query String Converter
- Infographic Chart Maker
Pingback: JSON to INI Converter - Turn JSON into INI Config Files