URL Builder

📖 Tool Introduction

URL Builder is a practical online tool built for front-end developers, QA engineers and operations staff who are tired of hand-assembling query strings and forgetting to encode non-ASCII characters. You simply type a base URL with its scheme, host and path at the top, then add key-value parameter rows one by one. The tool automatically percent-encodes every key and value according to RFC 3986 and joins them with a question mark or ampersand so that you end up with a complete, ready-to-copy request address. The entire process runs locally in your browser: no network request is ever made, so interface endpoints, tokens and other sensitive values never leave your device. A side-by-side table shows the original and encoded forms of each parameter, which makes it easy to verify every row. It is especially handy when debugging REST APIs, stitching monitoring dashboard links together, or generating shareable deep links for campaigns and documentation. Hand-building query strings by hand means constantly switching to an encoder tab to check whether a space became a plus or a percent-twenty, whether a Chinese character was escaped correctly, and whether you forgot the question mark on the first parameter. This tool removes all of that friction: you type friendly key-value pairs in plain language and the encoding happens automatically, with a side table that shows exactly what each parameter became after encoding so you can audit the result. It also handles the common edge case where the base URL already contains a question mark, switching to ampersand joins without you having to think about it.

✨ Key Features

• Dynamic parameter rows: click Add Parameter to insert a new key-value row; each row can be removed independently with no upper limit
• Standard percent-encoding: both keys and values follow the encodeURIComponent rules, so Chinese characters, spaces and symbols are escaped safely
• Smart separator: if the base URL already contains a question mark, an ampersand is used automatically to avoid double-question-mark bugs
• Encoding reference table: after building, every row shows the original key-value pair next to its encoded counterpart for quick verification
• One-click copy and download: the finished URL can be copied to the clipboard or saved as a plain text file
• Built-in example: load a realistic search-API parameter set with one click to see the whole flow immediately

📝 How to Use

1. Type your scheme, host and path into the Base URL field, for example https://api.example.com/search
2. Enter parameter names and values row by row; click Add Parameter whenever you need another row
3. Rows with an empty parameter name are skipped automatically during the build, so you do not have to delete them by hand
4. Click Build URL to see the assembled address on top and the encoding reference table below
5. Click Copy URL to put the result on your clipboard, or click Download to save it as a text file

⚠️ Notes

• Encoding rules: the tool applies RFC 3986 component encoding only to keys and values; the base URL itself is left untouched
• Empty rows: rows with an empty key are ignored, while an empty value is encoded as an empty string
• Sensitive data: avoid pasting long-lived production secrets here; the tool processes everything locally and never uploads anything
• Keyboard shortcut: press Ctrl+Enter inside any input to trigger the build and speed up your debugging loop
• Fully offline: all logic runs inside the browser with zero external requests, so it works on intranets and disconnected machines