Query String Parser – Parse Query Online (Free Tool)
Free online Query String Parser tool to parse and analyze URL query strings instantly. Extract key-value pairs from URL parameters and view them in an organized format. Perfect for debugging URLs and API calls. All parsing happens locally in your browser.
Example Output
Each parameter decoded and presented as a clean key/value pair.
{ utm_source: "newsletter", utm_campaign: "launch", page: "2" }What is Query String Parser?
Query String Parser splits a URL's ?key=value&key2=value2 portion into a clean key/value table. URL-decoding is handled automatically so percent-encoded characters appear readable. Useful when debugging tracking URLs, inspecting OAuth callbacks, or just trying to understand a complex link a tool generated.
Why use this tool?
- Stable behavior across visits — no surprise version drift
- Your data stays private — all processing happens locally in the browser
- No telemetry, no tracking pixels, no third-party scripts
- Works with very large inputs (multi-megabyte JSON, long regex patterns, big tables)
- No telemetry on the tokens, payloads, or code you paste in
How to use
- Paste a full URL or just the query-string portion (anything after the ?)
- See the parameters listed as key/value pairs
- Duplicate keys are grouped so you can spot repeated parameters
- Copy individual values or the full JSON breakdown
Examples
Decode a marketing UTM
?utm_source=newsletter&utm_medium=email&utm_campaign=launch%202024 → values cleanly separated, with "launch%202024" decoded to "launch 2024".
OAuth callback
Paste the callback URL after a sign-in flow — code, state, and error parameters appear as a table you can copy individually.
Duplicate keys
?tag=js&tag=react&tag=node — all three values listed under "tag" so you don't lose any.
Common use cases
- Debugging tracking and campaign URLs
- Inspecting OAuth/SSO callbacks during integration
- Extracting parameters from a generated share link
- Verifying URL builders produced the expected output
Troubleshooting
- Value still looks encoded (e.g. %20 instead of space).
- Some sources double-encode values (%2520). Run the value through URL Decode once or twice to fully restore it.
Frequently Asked Questions
A query string is the part of a URL after the ? character, containing key-value pairs separated by &. It is commonly used to pass data between web pages.
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