Running a site audit using SEO tools like Ahrefs is essential for identifying technical vulnerabilities, broken links, and crawl issues. However, seeing “403 Forbidden” or “Download Error” notifications in your Ahrefs Site Audit report can be frustrating.

When Ahrefs reports a 403 Forbidden error, it means the AhrefsBot attempted to crawl a specific URL on your domain, but your web server or Web Application Firewall (WAF) actively rejected the request. While your human visitors might access the page without any issues, blocking audit crawlers prevents you from getting an accurate technical health score for your website.

This guide explains why Ahrefs encounters 403 Forbidden and download errors, how these blocks impact your technical SEO performance, and the exact steps to whitelist crawlers and fix these errors permanently.

What Causes Ahrefs 403 Forbidden and Download Errors?

A 403 Forbidden HTTP status code indicates that the server understands the request, but refuses to authorize access. Download errors happen when the audit crawler times out, gets dropped by server limits, or fails to fetch page assets.

Here are the most common reasons why Ahrefs runs into these access blocks:

1. Firewall or WAF Rules (Cloudflare, Sucuri, Imperva): Security firewalls automatically detect high-frequency requests from automated bots and block them to prevent DDoS attacks or server overload.
2. Server-Level IP or User-Agent Blocking: Web hosting environments (such as cPanel settings, ModSecurity rules, or .htaccess configurations) often block known bot User-Agents by default.
3. Robots.txt Misconfigurations: If your server configuration conflicts with crawler permissions, access requests get dropped before the page renders. For a full breakdown on fixing server-level crawler directives, read our guide on How to Fix Broken Robots.txt Rules Blocking Googlebot.
4. Rate Limiting & Server Resource Caps: Low-cost shared hosting servers often terminate connections when a bot sends multiple requests per second, resulting in partial download failures.

Why You Must Fix Audit Crawler Access Blocks

Allowing Ahrefs and similar diagnostic crawlers to inspect your site is critical for maintaining overall site health:

• Uncovering Hidden Technical Bugs: If Ahrefs cannot access key sections of your site, it cannot flag critical issues like redirect loops or broken URLs. Learn how to address structural redirect issues in our article on 301 Redirect Loops and 404 Penalties.
• Preventing False Indexation Warnings: When crawlers encounter server blocks, Search Console often reports similar crawl anomalies. To understand how unexplained crawler errors manifest in search engines, see Why Google Search Console Shows Crawl Anomaly But No Error.
• Maintaining Accurate Health Scores: Blocked pages result in incomplete audit data, lowering your site’s health metrics artificially.

Step-by-Step Solutions: How to Resolve 403 Forbidden & Download Errors

Depending on your security setup and hosting environment, apply the following fixes:

Method 1: Whitelist AhrefsBot in Cloudflare / WAF

If your domain uses Cloudflare or another Web Application Firewall, create a custom security rule to allow AhrefsBot:

1. Log in to your Cloudflare Dashboard.
2. Select your domain and navigate to Security ➔ WAF ➔ Custom Rules.
3. Click Create Rule.
4. Name the rule (e.g., “Allow AhrefsBot”).
5. Set the condition: Choose User Agent, select contains, and enter AhrefsBot.
6. Set the action to Allow or Bypass (Bypass WAF / Managed Rules).
7. Save and Deploy the rule.

Method 2: Adjust Crawl Speed in Ahrefs Site Audit Settings

If your server drops connections due to rate limits or high resource usage:

1. Open your Ahrefs Project Settings.
2. Go to Site Audit Settings ➔ Crawler Settings.
3. Locate the Speed / Parallel Requests setting.
4. Lower the crawl speed (e.g., change from 10 requests per second to 1 or 2 requests per second).
5. Rerun the audit. This reduces the load on your server and prevents rate-limiting download errors.

Method 3: Whitelist Ahrefs IP Ranges on Your Web Host

If the block originates at the hosting level (cPanel / ModSecurity):

1. Access your hosting control panel or open a support ticket with your hosting provider.
2. Request that they whitelist the official AhrefsBot IP address ranges.
3. Ensure that your server’s ModSecurity rules do not automatically trigger a 403 response when encountering the AhrefsBot User-Agent string.

Evaluating Site Audits Across Multiple Tools

Resolving crawler access issues allows you to run comprehensive technical diagnostics across all major SEO tools.

To compare performance metrics and audit accuracy across platforms, explore these resources:

• Audit Platform Comparisons: Read our detailed analysis on SEMrush Site Audit vs Ahrefs Site Audit and Founds SEO Audit Tool vs Ahrefs.
• SEMrush Error Resolution: If you also use SEMrush for health monitoring, review Common SEO Errors Found in SEMrush Site Audit and learn How to Connect SEMrush and Google Search Console.
• Comprehensive Technical Auditing: To execute a complete manual inspection of your web architecture, follow The Ultimate Guide: How to Do a Technical SEO Audit in 2026 or use our Free SEO Audit Checklist.

How to Verify the Fix

Once you have updated your firewall rules or adjusted crawl speeds:

1. Go to your Ahrefs Site Audit dashboard.
2. Click Re-crawl Project.
3. Monitor the live log to confirm that URLs return a 200 OK HTTP response code instead of a 403 Forbidden status.
4. Verify that the Download Error count drops to zero.

Troubleshooting Summary

Cause of Error	Affected System	Solution
WAF / Bot Protection Block	Cloudflare / Sucuri	Create a Custom WAF Rule to Allow AhrefsBot
Server Rate Limiting	Hosting Server / cPanel	Lower crawl speed in Ahrefs project settings
IP / ModSecurity Restrictions	Web Server Firewall	Whitelist Ahrefs official IP ranges with host