Query String Builder - Build URL-Encoded Query Strings Online
Query String Builder
Build a Properly Encoded Query String
Understanding Query String Encoding
API Requests
Build a correctly encoded query string for a GET request without worrying about escaping special characters.
Shareable Links
Construct a link with multiple filter or search parameters to share with a teammate.
Testing & QA
Quickly assemble test query strings for a form or endpoint you're debugging.
Local Processing
Your key/value pairs never leave your browser — the string is built entirely client-side.
Why Encoding Matters
Characters like spaces, ampersands, and equals signs have special meaning inside a query string, so raw values containing them must be percent-encoded (or, for spaces, converted to a "+") to avoid corrupting the URL structure. This tool uses the browser's native URLSearchParams API, so every value is encoded exactly the way a real HTTP client or server would expect.
Key Takeaways
- Dynamic Rows: Add or remove key/value pairs as needed before building.
- Standards-Compliant Encoding: Uses the native URLSearchParams API for correct percent-encoding.
- Client-Side Only: All building happens locally in your browser — no data is ever sent to a server.