Developer utility
Query String Studio
Paste a URL or query string, edit parameters as a table, and copy the reconstructed result.
Your input stays in the browser — nothing is sent to a server. Privacy policy.
Best for
- Developers inspecting API redirect and OAuth callback URLs.
- Anyone debugging long URLs with encoded or repeated parameters.
- Teams building or testing query strings without guessing encoding rules.
When to use
- A URL arrives as a long, unreadable string of parameters.
- You need to change one parameter without retyping the rest.
- You want a clean query string to paste into a request or doc.
Input
Paste a URL or query string
Full URLs and bare query strings both work. Parameters appear in the table below as you type.
Parameters
Edit key–value pairs
No parameters yet. Paste a URL above or add a row manually.
Output
Reconstructed result
Output appears here once you have parameters.Try this example
Inspect an OAuth callback URL.
Action: paste the URL below into the input, then change the state value and copy the modified URL.
Raw callback URL
https://app.example.com/oauth/callback?code=xBz9_abc123&state=csrf-token-xyz&redirect_uri=https%3A%2F%2Fapp.example.com%2Fdashboard
What the table shows
Three parameters appear as separate rows: code, state, and redirect_uri — with the percent-encoded URI already decoded. Edit any value and copy a corrected URL without touching the others.
FAQ
Does the tool decode percent-encoded values automatically?
Yes. URLSearchParams decodes percent-encoding when parsing, so %20 appears as a space in the value field. The output re-encodes values correctly when you copy.
What if a key appears more than once in the URL?
Duplicate keys are preserved as separate rows. This mirrors how servers typically parse repeated parameters, such as ?tag=a&tag=b.
Can I build a query string from scratch without pasting a URL?
Yes. Leave the input blank, use the '+ Add row' button to enter keys and values, and copy the output directly.
Found an issue or have a suggestion? Report an issue or suggest an improvement.