When you update your robots.txt file, Google typically recrawls it within a few hours to days. However, in some cases like yours where the previous version accidentally blocked your entire site (Disallow: /), you'll want to expedite this process.

Here are the most effective methods to prompt Google to recrawl your robots.txt:

// Sample updated robots.txt you might want to use
User-agent: *
Allow: /important-page
Allow: /css/
Allow: /js/
Disallow: /private/
Sitemap: https://example.com/sitemap.xml

The most reliable method is through Google Search Console:

1. Navigate to URL Inspection tool
2. Enter your robots.txt URL (https://example.com/robots.txt)
3. Click Request Indexing

If Search Console isn't immediately available:

• Submit your sitemap through Search Console (this often triggers robots.txt recrawl)
• Fetch as Googlebot for your homepage
• Use the Indexing API if you have technical access:

// Example Python request using Indexing API
import requests

url = "https://example.com/robots.txt"
api_url = "https://indexing.googleapis.com/v3/urlNotifications:publish"

payload = {
    "url": url,
    "type": "URL_UPDATED"
}

headers = {
    "Content-Type": "application/json",
    "Authorization": "Bearer YOUR_ACCESS_TOKEN"
}

response = requests.post(api_url, json=payload, headers=headers)
print(response.json())

After taking these steps, verify the update:

curl -A "Googlebot" -I https://example.com/robots.txt

Check the Last-Modified header to confirm Google has fetched the new version.

To avoid similar situations:

• Always test changes in Google's robots.txt Tester tool first
• Consider using gradual changes rather than complete blocks
• Implement version control for your robots.txt file

# Example git hook to test robots.txt changes
#!/bin/sh
if git diff --cached --name-only | grep -q "robots.txt"; then
    python test_robots.py || exit 1
fi

When Googlebot caches your robots.txt file, it typically refreshes every 24-48 hours. However, in development scenarios where you've made critical changes (like accidentally blocking your entire site), waiting isn't ideal. Here's what's happening in your case:

// Problematic robots.txt (cached version)
User-agent: *
Allow: /page
Allow: /folder
Disallow: /

For urgent situations, try these technical approaches:

1. Google Search Console API Method

Use Google's Indexing API to force a recrawl (requires OAuth setup):

POST https://indexing.googleapis.com/v3/urlNotifications:publish
{
  "url": "https://example.com/robots.txt",
  "type": "URL_UPDATED"
}

2. Fetch as Google Tool (Legacy Method)

While deprecated, some developers still report success with:

1. Go to Google Search Console
2. URL Inspection tool
3. Enter "https://example.com/robots.txt"
4. Click "Test Live URL"
5. Click "Request Indexing"

Best practices for robots.txt in development environments:

# Safe transitional robots.txt
User-agent: *
Disallow: /private/
Disallow: /temp/
Allow: /*.css
Allow: /*.js
Allow: /*.png

Check recrawl status using curl:

curl -A "Googlebot" -I https://example.com/robots.txt

Monitor Last-Modified header changes to confirm update.

If your site remains blocked after 72 hours:

# Emergency override robots.txt
User-agent: *
Disallow:
Sitemap: https://example.com/sitemap.xml

Then submit a reconsideration request through Search Console.