TheDualWeb

Browser extension

Know more before you reach out.

Check authorized contact number availability from Chrome or Firefox before your team reaches out. Built for teams working from an existing, authorized contact list.

Selected files are read locally. Only the normalized authorized number list is sent for the requested check, and number lists or results are not retained after processing.

ChromeAdd to ChromeFirefoxAdd to Firefox
Number check•••
+62 812 3456 7890Available
+60 12 345 6789Available
+1 415 555 2671Unavailable

Results stay in your browser until you close the session.

Inside the extension

A clear path from pairing to results.

Connect an authorized device, add a list by file or direct entry, then review availability without leaving the extension.

Pair securely in TheDualWeb browser extension
Pair securelyConnect an authorized device by scanning a time-limited QR code.
Select a local list in TheDualWeb browser extension
Select a local listRead one number per line from a local TXT or single-column CSV file.
Enter numbers directly in TheDualWeb browser extension
Enter numbers directlyPaste an authorized list and prepare it for one clear scan.

Straightforward flow

Four Steps. No Guesswork.

  1. 01

    Install

    Add Verify from the Chrome Web Store or Firefox Add-ons.

  2. 02

    Connect

    Complete the secure device pairing flow.

  3. 03

    Check

    Paste an authorized list or select a local TXT or single-column CSV file.

  4. 04

    Review

    See availability results, then take your next step.

Use it smart. Keep it responsible.

Only check numbers you own or have permission to contact. TheDualWeb is not affiliated with, endorsed by, or sponsored by WhatsApp or Meta.

Privacy details
Person using TheDualWeb responsibly