When Chrome Developer Tools (DevTools) are open and the page is refreshed, it throws a “No Internet” screen with ERR_INTERNET_DISCONNECTED.

This guide walks you through every cause and its solution, with visuals and best practices.

🚩 Why This Happens

This error can be triggered even when you’re online, typically due to:

• DevTools misconfigurations
• Simulated offline mode
• Caching issues
• Extension or proxy interference

✅ Step-by-Step Fixes

🔹 Step 1: Check if “Disable Cache” is ON

When DevTools is open, Chrome disables caching by default.

🔍 Steps:

1. Open DevTools (F12 or Ctrl + Shift + I).
2. Go to the Network tab.
3. Uncheck the “Disable cache” checkbox (at the top).

🧠 Note: This setting is only active when DevTools is open.

🔹 Step 2: Ensure DevTools is Set to “Online”

DevTools lets you simulate offline networks for testing — make sure it’s not stuck in “Offline” mode.

🔍 Steps:

1. In DevTools, go to Network tab.
2. Look at the top bar → Click the dropdown labeled “Online” or “Offline”.
3. Select “Online” if not already selected.

📸 You should see:

Throttling: [ Online ▼ ]

🔹 Step 3: Turn Off Chrome Extensions (Temporarily)

Some Chrome extensions (e.g., VPNs, privacy blockers, proxies) interfere with DevTools.

🔍 Steps:

1. Go to: chrome://extensions
2. Disable all extensions.
3. Refresh the page with DevTools open.
4. If the issue goes away, re-enable extensions one by one to find the culprit.

🔹 Step 4: Disable Antivirus/Firewall (Temporarily)

Security software may block outgoing connections when debugging tools are in use.

🔍 Steps:

• Temporarily disable antivirus, firewall, or network protection software.
• Retry refreshing the page.

If it works, add Chrome to the allowed list of your security tools.

🔹 Step 5: Check Proxy Settings

Misconfigured proxy settings (especially in corporate networks or VPNs) can block Chrome connections.

🔍 Steps:

1. Go to Chrome Settings → chrome://settings/
2. Scroll down and click “System”.
3. Click “Open your computer’s proxy settings”.
4. Ensure:
   • No proxy is active, unless intentionally set.
   • Automatic proxy detection is off (if not needed).

🔹 Step 6: Test in Incognito Mode

Incognito mode disables extensions by default.

🔍 Steps:

• Press Ctrl + Shift + N to open an Incognito window.
• Open DevTools → Refresh page.

If it works, the issue is most likely caused by extensions or cache.

🔹 Step 7: Update or Reinstall Chrome

Corrupted Chrome settings or outdated versions can lead to unexpected network behavior.

🔍 Steps:

• Go to chrome://settings/help
• Chrome will check and apply updates.
• Restart the browser.

If issues persist, consider uninstalling and reinstalling Chrome completely.

💡 Pro Tips

• ✅ Use Chrome Profiles to isolate dev tools and avoid cross-interference.
• 🔒 Always back up your Chrome settings/bookmarks before resetting.
• 🧪 Use the “Network Conditions” tab (under DevTools > More Tools) to simulate slower networks safely — but turn it off afterward.

🧑‍💻 Common Use Cases Where This Error Happens

✅ Final Checklist Before Refreshing

• “Disable Cache” is unchecked
• Throttling is set to Online
• VPN/Proxy is disabled
• Extensions are disabled (try Incognito)
• Antivirus/Firewall is not interfering
• Chrome is up to date