Query String Builder is a free, browser-based tool built for developers and marketers assembling URLs with tracking or filter parameters.
How to use the Query String Builder
- Optionally enter a base URL.
- Add up to six key/value parameter pairs.
- Click Build URL.
- Copy the fully encoded URL or query string.
Why use FreeToolsNets's Query String Builder?
- 100% free, with no usage limits and no account required.
- Everything runs locally in your browser — nothing you type is uploaded or stored on a server.
- Works on desktop, tablet and mobile in any modern browser.
- No installation, no plugins, and no ads blocking the tool itself.
- Part of FreeToolsNets's Website & SEO Tools collection.
Frequently asked questions
Are special characters encoded?
Yes — every key and value is passed through encodeURIComponent automatically.
Can I parse an existing URL instead?
Use the URL Parser tool on FreeToolsNets to break an existing URL into its parts.
Is this tool free to use?
Yes, completely free on FreeToolsNets, with no sign-up and no limits.
Is my data sent to a server?
No. Everything runs locally in your browser using JavaScript — nothing you enter is uploaded anywhere.
Does it work on mobile?
Yes, the widget is fully responsive and works on phones, tablets and desktops.