Free Web ToolsBuild a URL query from keys and values. Keep repeated keys, append to or replace an existing query, then copy or save the URL as TXT.
UTF-8 limits: base URL 8,000 bytes, each key 200 bytes, each value 2,000 bytes, total input 100,000 bytes, generated URL 16,000 bytes. Up to 100 rows. Inputs and results are neither stored nor sent.
Build search URLs containing spaces and ampersands, or filters with repeated keys.
Trying an example replaces the input and settings and runs the tool. Restore previous input restores the input and settings from before the latest example.
After trying multiple examples, repeat Restore previous input to return to your original input. History is kept only in this page; restore any input you need before closing it.
https://example.com/search?lang=ja#results Mode: Append q = hello world & + tag = web tag = tools
https://example.com/search?lang=ja&q=hello+world+%26+%2B&tag=web&tag=tools#results
https://example.com/search?old=1#results Mode: Replace q = tea & cake
https://example.com/search?q=tea+%26+cake#results
Compare the full URL with the query-only output. Spaces become +, an ampersand inside a value becomes %26, and a literal + becomes %2B. Append retains lang=ja; replace removes old=1. Both retain #results.
Enter unencoded keys and values. Entering an already encoded %26 produces %2526, which is double encoding. Use a complete http/https URL without credentials. Limits are 100 rows and, in UTF-8 bytes, 8,000 for the base URL, 200 per key, 2,000 per value, 100,000 total input and 16,000 output. Check how the destination handles repeated keys.
Verification: the existing build function and browser interactions are checked for append and replace modes, repeated keys, spaces, & and +, and fragment preservation. The URL is not fetched and server-side parsing is not tested.
Enter a complete http/https URL and add one key/value pair per row. Repeated keys keep their input order. Rows with an empty key and value are unused. A value without a key is an error; an empty value is written as key=.
Enter unencoded text. Spaces become +, literal + becomes %2B and % becomes %25. Leading/trailing whitespace and line breaks in keys and values are retained.
Append mode retains the spelling of the existing query, including %20. Replace mode removes the old query and uses only your rows. The fragment after # is retained.
Browser URL handling may normalize hostnames, letter case, default ports and paths. This tool never opens the generated URL. Editing clears the result; build again to update it. Reset clears the base URL, rows and result while retaining the selected mode. The example selects append mode.
Yes. For example, tag=web&tag=tools keeps both values in input order.
New rows are encoded as literal text. Entering %20 produces %2520. To represent a space, enter an actual space.
Only the generated URL is saved as UTF-8 TXT without a BOM or added newline. The 16,000-byte tool limit is separate from limits imposed by the destination.
Share only the tool name and public URL. Your input and results are not included.
Keep any content you need before clearing. This tool does not autosave inputs or results. Reloading or closing the page, clearing inputs or resetting may discard your work.
Favorites and language preferences are stored separately and may be lost when site data is cleared. Tool resets and site-data deletion do not delete files already downloaded to your device.