To fix the issue of contacts not showing up on WhatsApp, you can try the following methods:

Android:

  1. Check permissions:

    • Open Settings.
    • Select Apps or App Management.
    • Tap on WhatsApp.
    • Choose Permissions.
    • Ensure Contacts permission is enabled.

  2. Refresh contacts:

    • Open WhatsApp.
    • Tap on the chat bubble at the bottom right corner.
    • Tap on the ⋮ (three dots) in the top right corner.
    • Tap on Refresh.

  3. Force WhatsApp Sync:

    • Open Settings.
    • Select Passwords & accounts or Users and accounts.
    • Tap on Account sync.
    • Toggle on Contacts to force a sync.

  4. Enable 'Show all contacts' option:

    • Go to the WhatsApp homepage.
    • Tap on Settings > Settings > Contacts.
    • Ensure 'Show all contacts' is ticked.

iPhone:

  1. Add or update contact details:

    • Tap the number of the contact at the top of the screen in WhatsApp.
    • Either create a new contact or add to an existing one, ensuring the correct country code is included.

  2. Refresh contacts:

    • Open WhatsApp.
    • Tap on the chat bubble at the bottom right corner.
    • Tap on the ⋮ (three dots) in the top right corner.
    • Tap on Refresh.

  3. Clear app cache or data:

    • Open Settings.
    • Select Apps or App Management.
    • Tap on WhatsApp.
    • Clear cache or data (remember to keep the app installed).

  4. Update WhatsApp:

    • Go to the App Store and check for WhatsApp updates.

  5. Use a professional tool (Android only):

    • Consider using a professional tool like DroidKit to recover or manage WhatsApp contacts.

Remember to check if the country code is correctly inserted for international contacts, and ensure that WhatsApp has the necessary permissions to access your contacts.