HTTP Status Codes and Their SEO Impact: A Complete Guide

Introduction

HTTP status codes are three-digit responses that servers send to indicate the result of a client's request. These codes have significant implications for SEO, as they tell search engine crawlers how to treat URLs.

Status Code Categories

2xx Success

Code	Name	Meaning	SEO Impact
200	OK	Request successful	✅ Index normally
201	Created	Resource created	Rare in web browsing
204	No Content	Successful, no content	Uncommon for pages

3xx Redirection

Indicates the resource has moved.

301 Moved Permanently

http

HTTP/1.1 301 Moved Permanently
Location: https://example.com/new-page

When to use:

Permanent URL changes
Site migrations
HTTPS migrations
Consolidating duplicate content

SEO Impact:

✅ Passes ~90-99% of link equity
✅ Old URL replaced with new in index
✅ Signals permanence to crawlers

✅ SuccessBest Practice

Always use 301 for permanent changes. Crawlers will eventually stop checking the old URL.

302 Found (Temporary Redirect)

http

HTTP/1.1 302 Found
Location: https://example.com/temp-page

When to use:

A/B testing
Temporary promotions
Maintenance pages
Country-specific redirects

SEO Impact:

⚠️ Original URL stays in index
⚠️ May not pass full link equity
⚠️ Crawlers continue checking original URL

307 Temporary Redirect

Similar to 302 but preserves request method (POST stays POST).

308 Permanent Redirect

Similar to 301 but preserves request method.

4xx Client Errors

Indicates a client-side error.

404 Not Found

http

HTTP/1.1 404 Not Found

When to use:

Page deleted without replacement
URL never existed
Resource intentionally unavailable

SEO Impact:

✅ Eventually removed from index
✅ Link equity is lost
✅ Signals to crawlers: don't return

ℹ️ InfoNormal Behavior

404 errors are normal. Even healthy sites have them. Focus on fixing important broken links, not achieving zero 404s.

410 Gone

http

HTTP/1.1 410 Gone

When to use:

Permanently deleted content
Want faster de-indexing than 404

SEO Impact:

✅ Faster removal from index than 404
✅ Crawlers stop checking sooner
✅ Signals permanent deletion

Use 410 for:

Expired promotions
Discontinued products (with no replacement)
Removed articles

429 Too Many Requests

http

HTTP/1.1 429 Too Many Requests
Retry-After: 3600

When to use:

Rate limiting implemented
Crawler exceeding limits

SEO Impact:

⚠️ Crawler will retry later
⚠️ May slow indexing
✅ Use Retry-After header to help crawlers

5xx Server Errors

Indicates a server-side error.

500 Internal Server Error

http

HTTP/1.1 500 Internal Server Error

SEO Impact:

⚠️ Temporary: Crawler retries later
❌ Persistent: May be de-indexed
❌ Negative ranking signal if common

503 Service Unavailable

http

HTTP/1.1 503 Service Unavailable
Retry-After: 3600

When to use:

Planned maintenance
Temporary overload

SEO Impact:

✅ Crawler treats as temporary
✅ Won't immediately de-index
✅ Use for maintenance windows

nginx.confnginx

# nginx maintenance mode
if (-f $document_root/maintenance.html) {
return 503;
}

error_page 503 @maintenance;

location @maintenance {
add_header Retry-After 3600 always;
return 503 /maintenance.html;
}

Common Redirect Patterns

Site Migration

.htaccessapache

# Old domain to new domain
RewriteEngine On
RewriteCond %{HTTP_HOST} ^old-domain\.com$ [NC]
RewriteRule ^(.*)$ https://new-domain.com/$1 [L,R=301]

HTTPS Migration

.htaccessapache

# Force HTTPS
RewriteEngine On
RewriteCond %{HTTPS} off
RewriteRule ^(.*)$ https://%{HTTP_HOST}/$1 [L,R=301]

Trailing Slash Normalization

.htaccessapache

# Add trailing slash
RewriteCond %{REQUEST_URI} !/$
RewriteCond %{REQUEST_FILENAME} !-f
RewriteRule ^(.*)$ $1/ [L,R=301]

Redirect Chains and Loops

Redirect Chain (Bad)

text

example.com/page-1 
→ 301 → example.com/page-2 
→ 301 → example.com/page-3

Problems:

❌ Wastes crawl budget
❌ Loses link equity at each hop
❌ Slower user experience
❌ May not be fully followed

Solution: Direct redirects

text

example.com/page-1 → 301 → example.com/page-3
example.com/page-2 → 301 → example.com/page-3

Redirect Loop (Fatal)

text

example.com/page-a → 301 → example.com/page-b
example.com/page-b → 301 → example.com/page-a

Impact:

❌ Crawlers give up
❌ Page becomes unreachable
❌ Will be de-indexed

Custom Error Pages

404 Page Best Practices

404.htmlhtml

<!DOCTYPE html>
<html>
<head>
<title>Page Not Found - Example Site</title>
</head>
<body>
<h1>404: Page Not Found</h1>
<p>The page you're looking for doesn't exist.</p>

<!-- Help users find what they need -->
<nav>
  <a href="/">Home</a>
  <a href="/search">Search</a>
  <a href="/popular">Popular Pages</a>
</nav>

<!-- Log broken links -->
<script>
  logBrokenLink(window.location.pathname);
</script>
</body>
</html>

Must return 404 status, not 200 with "Not Found" message!

Soft 404s (Avoid)

A "soft 404" returns 200 OK but shows "not found" content:

http

HTTP/1.1 200 OK

<html>
<body>
  <h1>Page Not Found</h1>
</body>
</html>

Problems:

❌ Confuses crawlers
❌ Wastes crawl budget
❌ Pages stay in index unnecessarily

Monitoring Status Codes

Server Logs

analyze-logs.shbash

# Count status codes
awk '{print $9}' access.log | sort | uniq -c | sort -rn

# Find 404s
grep " 404 " access.log | awk '{print $7}' | sort | uniq -c | sort -rn

# Find redirect chains
grep " 301 " access.log | awk '{print $7}'

Google Search Console

Monitor:

Coverage Report: Shows indexing issues
Status Codes: Filter by error type
Not Found (404): List of 404 URLs
Redirect Errors: Chains and loops

Third-Party Tools

Screaming Frog SEO Spider
Ahrefs Site Audit
Semrush Site Audit

Best Practices Summary

Scenario	Use	Avoid
Permanent move	301	302
Temporary move	302	301
Deleted forever	410	404 then 301
Deleted, no rush	404	Soft 404
Maintenance	503	404 or 500
Rate limiting	429	403 or 500

Common Mistakes

1. Using 302 for Permanent Changes

🚨 DangerWrong

Using 302 for permanent changes confuses crawlers and may not pass link equity.

2. Redirect Chains

Always redirect directly to final destination.

3. Not Using 410

For permanently deleted content, 410 signals faster removal than 404.

4. Soft 404s

Always return proper 404 status code, not 200 with error message.

Conclusion

HTTP status codes are fundamental to how crawlers interpret your site. Use them correctly to:

✅ Preserve link equity during migrations
✅ Help crawlers understand content status
✅ Optimize crawl budget
✅ Provide better user experience

Key Takeaways:

Use 301 for permanent redirects
Use 302 only for temporary redirects
Return real 404s, not soft 404s
Avoid redirect chains
Monitor status codes regularly
Fix critical errors promptly

Next Steps

Introduction

Status Code Categories

2xx Success

Code	Name	Meaning	SEO Impact
200	OK	Request successful	✅ Index normally
201	Created	Resource created	Rare in web browsing
204	No Content	Successful, no content	Uncommon for pages

3xx Redirection

Indicates the resource has moved.

301 Moved Permanently

http

HTTP/1.1 301 Moved Permanently
Location: https://example.com/new-page

When to use:

Permanent URL changes
Site migrations
HTTPS migrations
Consolidating duplicate content

SEO Impact:

✅ Passes ~90-99% of link equity
✅ Old URL replaced with new in index
✅ Signals permanence to crawlers

✅ SuccessBest Practice

Always use 301 for permanent changes. Crawlers will eventually stop checking the old URL.

302 Found (Temporary Redirect)

http

HTTP/1.1 302 Found
Location: https://example.com/temp-page

When to use:

A/B testing
Temporary promotions
Maintenance pages
Country-specific redirects

SEO Impact:

⚠️ Original URL stays in index
⚠️ May not pass full link equity
⚠️ Crawlers continue checking original URL

307 Temporary Redirect

Similar to 302 but preserves request method (POST stays POST).

308 Permanent Redirect

Similar to 301 but preserves request method.

4xx Client Errors

Indicates a client-side error.

404 Not Found

http

HTTP/1.1 404 Not Found

When to use:

Page deleted without replacement
URL never existed
Resource intentionally unavailable

SEO Impact:

✅ Eventually removed from index
✅ Link equity is lost
✅ Signals to crawlers: don't return

ℹ️ InfoNormal Behavior

404 errors are normal. Even healthy sites have them. Focus on fixing important broken links, not achieving zero 404s.

410 Gone

http

HTTP/1.1 410 Gone

When to use:

Permanently deleted content
Want faster de-indexing than 404

SEO Impact:

✅ Faster removal from index than 404
✅ Crawlers stop checking sooner
✅ Signals permanent deletion

Use 410 for:

Expired promotions
Discontinued products (with no replacement)
Removed articles

429 Too Many Requests

http

HTTP/1.1 429 Too Many Requests
Retry-After: 3600

When to use:

Rate limiting implemented
Crawler exceeding limits

SEO Impact:

⚠️ Crawler will retry later
⚠️ May slow indexing
✅ Use Retry-After header to help crawlers

5xx Server Errors

Indicates a server-side error.

500 Internal Server Error

http

HTTP/1.1 500 Internal Server Error

SEO Impact:

⚠️ Temporary: Crawler retries later
❌ Persistent: May be de-indexed
❌ Negative ranking signal if common

503 Service Unavailable

http

HTTP/1.1 503 Service Unavailable
Retry-After: 3600

When to use:

Planned maintenance
Temporary overload

SEO Impact:

✅ Crawler treats as temporary
✅ Won't immediately de-index
✅ Use for maintenance windows

nginx.confnginx

# nginx maintenance mode
if (-f $document_root/maintenance.html) {
return 503;
}

error_page 503 @maintenance;

location @maintenance {
add_header Retry-After 3600 always;
return 503 /maintenance.html;
}

Common Redirect Patterns

Site Migration

.htaccessapache

# Old domain to new domain
RewriteEngine On
RewriteCond %{HTTP_HOST} ^old-domain\.com$ [NC]
RewriteRule ^(.*)$ https://new-domain.com/$1 [L,R=301]

HTTPS Migration

.htaccessapache

# Force HTTPS
RewriteEngine On
RewriteCond %{HTTPS} off
RewriteRule ^(.*)$ https://%{HTTP_HOST}/$1 [L,R=301]

Trailing Slash Normalization

.htaccessapache

# Add trailing slash
RewriteCond %{REQUEST_URI} !/$
RewriteCond %{REQUEST_FILENAME} !-f
RewriteRule ^(.*)$ $1/ [L,R=301]

Redirect Chains and Loops

Redirect Chain (Bad)

text

example.com/page-1 
→ 301 → example.com/page-2 
→ 301 → example.com/page-3

Problems:

❌ Wastes crawl budget
❌ Loses link equity at each hop
❌ Slower user experience
❌ May not be fully followed

Solution: Direct redirects

text

example.com/page-1 → 301 → example.com/page-3
example.com/page-2 → 301 → example.com/page-3

Redirect Loop (Fatal)

text

example.com/page-a → 301 → example.com/page-b
example.com/page-b → 301 → example.com/page-a

Impact:

❌ Crawlers give up
❌ Page becomes unreachable
❌ Will be de-indexed

Custom Error Pages

404 Page Best Practices

404.htmlhtml

<!DOCTYPE html>
<html>
<head>
<title>Page Not Found - Example Site</title>
</head>
<body>
<h1>404: Page Not Found</h1>
<p>The page you're looking for doesn't exist.</p>

<!-- Help users find what they need -->
<nav>
  <a href="/">Home</a>
  <a href="/search">Search</a>
  <a href="/popular">Popular Pages</a>
</nav>

<!-- Log broken links -->
<script>
  logBrokenLink(window.location.pathname);
</script>
</body>
</html>

Must return 404 status, not 200 with "Not Found" message!

Soft 404s (Avoid)

A "soft 404" returns 200 OK but shows "not found" content:

http

HTTP/1.1 200 OK

<html>
<body>
  <h1>Page Not Found</h1>
</body>
</html>

Problems:

❌ Confuses crawlers
❌ Wastes crawl budget
❌ Pages stay in index unnecessarily

Monitoring Status Codes

Server Logs

analyze-logs.shbash

# Count status codes
awk '{print $9}' access.log | sort | uniq -c | sort -rn

# Find 404s
grep " 404 " access.log | awk '{print $7}' | sort | uniq -c | sort -rn

# Find redirect chains
grep " 301 " access.log | awk '{print $7}'

Google Search Console

Monitor:

Coverage Report: Shows indexing issues
Status Codes: Filter by error type
Not Found (404): List of 404 URLs
Redirect Errors: Chains and loops

Third-Party Tools

Screaming Frog SEO Spider
Ahrefs Site Audit
Semrush Site Audit

Best Practices Summary

Scenario	Use	Avoid
Permanent move	301	302
Temporary move	302	301
Deleted forever	410	404 then 301
Deleted, no rush	404	Soft 404
Maintenance	503	404 or 500
Rate limiting	429	403 or 500

Common Mistakes

1. Using 302 for Permanent Changes

🚨 DangerWrong

Using 302 for permanent changes confuses crawlers and may not pass link equity.

2. Redirect Chains

Always redirect directly to final destination.

3. Not Using 410

For permanently deleted content, 410 signals faster removal than 404.

4. Soft 404s

Always return proper 404 status code, not 200 with error message.

Conclusion

HTTP status codes are fundamental to how crawlers interpret your site. Use them correctly to:

✅ Preserve link equity during migrations
✅ Help crawlers understand content status
✅ Optimize crawl budget
✅ Provide better user experience

Key Takeaways:

Use 301 for permanent redirects
Use 302 only for temporary redirects
Return real 404s, not soft 404s
Avoid redirect chains
Monitor status codes regularly
Fix critical errors promptly