HTTP Status Code Checker
Monitor website uptime, detect broken links, and analyze HTTP responses instantly. Check single URLs or bulk validate up to 500 URLs with detailed status codes, redirect chains, and performance metrics.
Success
Request completed successfully
Redirect
Resource moved to new location
Client Error
Bad request or resource not found
Server Error
Server failed to fulfill request
SEO Auditing
Find and fix broken links that hurt search rankings
Uptime Monitoring
Check if your websites and APIs are online
Migration Testing
Verify redirects after site redesign or domain change
Powered by Go's net/http package • Real-time HTTP checks
Complete Guide to HTTP Status Codes and Website Monitoring
Master website uptime monitoring with our comprehensive HTTP status checker. Learn how to detect broken links, analyze redirect chains, troubleshoot server errors, and maintain healthy websites. Essential for developers, SEO professionals, and webmasters managing online properties.
What HTTP Status Codes Tell You About Your Website
Every time someone visits your website, their browser sends an HTTP request to your server, and your server responds with a three-digit status code that communicates what happened. These codes are invisible to regular visitors but critical for diagnosing problems. A 404 Not Found means the page doesn't exist—terrible for user experience and SEO. A 500 Internal Server Error means your server crashed while processing the request. A 301 Moved Permanently tells search engines to update their index to a new URL. Understanding these codes prevents lost traffic, maintains search rankings, and keeps users happy.
Why Status Codes Matter for Your Business:
💡 Real-World Example: The Hidden 404 Problem
An e-commerce company redesigned their site and implemented 301 redirects for all old URLs—or so they thought. Six months later, traffic was down 30%. A status check revealed 1,247 product pages returning 404 errors because someone forgot to migrate the /products/ subdirectory. By the time they discovered this through manual reports, they'd lost an estimated $180,000 in organic search traffic.
The fix: Running bulk status checks on all sitemap URLs immediately after launch would have caught this in minutes instead of months. This is exactly why systematic status monitoring isn't optional—it's business-critical infrastructure.
Understanding the Five Status Code Categories
HTTP status codes follow a simple pattern: the first digit indicates the category. Knowing these categories helps you diagnose problems instantly without memorizing every individual code. Here's what each range actually means in practice, not just theory.
Success Codes
Request completed successfully—everything worked
This is what you want for every page. The server found the resource, processed the request, and sent back exactly what was requested. For SEO, consistent 200 responses = healthy site.
Common in APIs and forms. When you POST data (submit a contact form, create an account), the server returns 201 if it successfully created the new resource. The response usually includes the URL for the newly created item.
Request succeeded but there's intentionally nothing to return. Used for DELETE operations or updates where you don't need the server to send data back—just confirmation it worked.
Redirect Codes
Resource moved—look elsewhere for the content
The content moved to a new URL and isn't coming back. Search engines update their index to the new location and transfer most of the SEO equity (link juice). This is your go-to for site redesigns, domain changes, or retiring old content.
Content temporarily lives at a different URL but will return to the original location. Search engines keep indexing the original URL. Often misused when people actually mean 301.
Like 302 but preserves the HTTP method. If the original request was POST, the redirect is also POST. Modern alternative to 302 with more predictable behavior.
Like 301 but preserves the HTTP method. Growing in adoption for REST APIs where maintaining POST/PUT/DELETE through redirects matters. Same SEO benefits as 301.
⚠️ Redirect Chain Warning
Bad: example.com → 301 → www.example.com → 301 → www.example.com/home → 200
This three-hop chain wastes server resources, slows page load by 300-500ms, and dilutes SEO value. Each redirect loses approximately 10-15% of link equity.
Good: example.com → 301 → www.example.com/home → 200
Always redirect directly to the final destination in one hop. Use our bulk checker to find these chains.
Client Error Codes
Problem with the request—not the server
The server is working fine, but the requested resource doesn't exist. This is the error everyone recognizes. Common causes: typos in URLs, deleted content, broken internal links, outdated sitemap entries.
The resource exists but you're not allowed to access it. Common for admin panels, private content, IP-restricted areas, or misconfigured file permissions.
Similar to 403 but specifically means "you need to log in first." The server is challenging you to provide credentials before granting access.
Like 404 but specifically communicates "this resource was here, we deliberately removed it, and it's never coming back." Tells search engines to remove the URL from their index faster than 404.
You're making requests too quickly. APIs use this to prevent abuse. Our bulk checker respects rate limits by default (max 10 requests/second per domain).
Server Error Codes
Something broke on the server—not your fault
The server encountered an unexpected condition. This is the generic "we broke something" error. Could be bad code, database connection failure, PHP fatal error, missing dependencies—anything really.
Your server is working, but it got an invalid response from an upstream server (load balancer, reverse proxy, or backend API). Common with Nginx, Apache proxies, or microservices architectures.
Server is temporarily unable to handle requests. Usually means overloaded (too much traffic), undergoing maintenance, or a critical dependency is down. The key word is temporary—things should recover.
Like 502 but specifically means the upstream server didn't respond in time. Your proxy waited 30-60 seconds and gave up. Usually indicates slow database queries, long-running scripts, or overwhelmed backend services.
How to Check HTTP Status Codes Effectively
Single URL Checking: Quick Diagnostics
When you need to verify a specific page, test a redirect, or troubleshoot a user-reported issue, single URL checking gives you instant detailed analysis. Here's how to get the most value:
Always include the protocol (https:// or http://). Many issues stem from protocol mismatches. If you're checking www.example.com, verify both https://example.com and https://www.example.com because these might return different status codes if redirects aren't configured properly.
✗ www.example.com/products/widget
GET retrieves the full page—use this for normal page checking. HEAD fetches only headers without the body content, making it faster for bulk operations or when you only need metadata. POST is useful for testing form endpoints or API routes that require POST requests.
Toggle "Follow Redirects" ON to see the complete redirect chain. This reveals hidden problems like redirect loops, unnecessary redirect hops, or chains that eventually lead to 404s. Without this, you only see the first redirect (301 or 302) without knowing where it ultimately lands.
Response Time: How quickly the server responds. Under 200ms is excellent. Over 1000ms indicates performance problems. Compare response times across different URLs to identify slow endpoints.
SSL Certificate Info: Validity status, expiration date, issuer. Critical for HTTPS sites. Expired certificates trigger browser warnings that scare away 95% of visitors.
Server Headers: Reveals technology stack (Apache, Nginx, Cloudflare), caching configuration, security headers. Use this to understand infrastructure and identify missing security protections.
Health Score: Our algorithm considers status code, response time, security headers, redirect chain length, and SSL validity to give you a 0-100 score. Aim for 90+.
Bulk URL Checking: Site-Wide Audits
Checking hundreds of URLs manually is impossible. Bulk checking lets you validate entire sitemaps, audit content migrations, or monitor all your important pages in one operation. Here's your workflow:
Enter one URL per line. Copy-paste from Excel, export from your CMS, extract from your sitemap.xml, or use Google Search Console's crawl errors report. The tool automatically removes duplicates and validates format before checking.
https://example.com/about
https://example.com/products/widget-a
https://example.com/products/widget-b
https://example.com/blog/article-1
The concurrency slider (1-50) controls how many URLs we check simultaneously. Higher numbers finish faster but generate more server load. Use these guidelines:
Balanced speed and server-friendliness. Checks 100 URLs in ~10 seconds. Safe for most websites including shared hosting.
Maximum speed. Checks 100 URLs in ~3 seconds. Use only for robust servers or checking external domains.
Minimal server impact. Checks 100 URLs in ~30 seconds. Use for weak servers, rate-limited APIs, or being extra cautious.
Start with 10 concurrency. If your server handles it well, increase gradually. Watch server load during the check.
After checking completes, you get a comprehensive dashboard with filterable results:
After redesigning or migrating your site, check all old URLs to ensure redirects work correctly. Prevents the disaster scenario where thousands of indexed pages return 404.
Export your backlink profile from Ahrefs or SEMrush. Check all target URLs to verify they return 200 OK. Dead backlinks waste valuable SEO equity.
Extract URLs from sitemap.xml and check them all. Sitemaps shouldn't contain 404s, redirects, or noindex pages. Search engines penalize dirty sitemaps.
E-commerce sites with thousands of products need regular checks. Discontinued products should 301 to category pages or 410 Gone—never 404.
After changing CDN providers or SSL certificates, bulk check all assets (images, CSS, JS files) to ensure everything serves properly over HTTPS.
Managing multiple client sites or brand domains? Bulk check key pages across all properties daily to catch downtime before customers do.
Why Redirect Chains Kill Performance and SEO
Every redirect adds latency. Your browser must make a complete round-trip to the server, receive the redirect, then make another request to the new location. On mobile networks with 200ms ping times, a three-hop redirect chain adds 600ms of pure waiting before content starts loading. Users perceive pages that take over 2 seconds as "slow" and abandon them. Search engines factor page speed into rankings. Redirect chains are silent performance killers.
❌ Bad: Three-Hop Redirect Chain
SEO value lost: ~25-30% from multiple hops
Mobile experience: Terrible on 3G
✓ Good: Single Redirect
SEO value lost: ~10% from single redirect
Mobile experience: Acceptable
⚠️ The Redirect Loop Problem
A redirect loop happens when URL A redirects to URL B, which redirects back to URL A. Browsers detect this after 10-20 attempts and show "too many redirects" errors. Users see nothing. Our checker detects loops immediately by tracking visited URLs.
example.com/page-b → 301 → example.com/page-a
Loop detected: page-a → page-b → page-a
Common cause: Conflicting redirect rules in .htaccess or multiple plugins/middlewares fighting over URL structure. Check your redirect configuration carefully when you see loops.
💡 Protocol and Subdomain Redirect Strategy
Best practice: Choose ONE canonical URL format and redirect everything else to it in a single hop. Most sites choose https://www (for better cookie scoping) or https:// without www (for shorter URLs).
Troubleshooting Common HTTP Status Problems
Problem: Mass 404 Errors After Site Redesign
Symptom: Traffic drops 40-60% after launching new design. Bulk checker shows hundreds of 404s. Google Search Console shows spike in crawl errors.
- URL structure changed but no redirect rules implemented
- Redirect rules created but .htaccess syntax errors prevent them from working
- New CMS generates different URL patterns than old site
- Redirects added for main pages but missed images, PDFs, or old blog posts
- Export complete list of old URLs from Google Search Console or server logs
- Map each old URL to its new equivalent (or category page if removed)
- Implement 301 redirects for ALL old URLs—no exceptions
- Use our bulk checker to verify every redirect works correctly
- Monitor Search Console for 2-3 weeks to catch any missed URLs
Problem: Intermittent 500 Errors Under Load
Symptom: Site works fine at night, returns 500 errors during business hours. Status checks show 200 OK sometimes, 500 other times.
- Database connection pool exhausted under high traffic
- PHP memory limit hit when processing large requests
- Server CPU/RAM maxed out—no resources for new requests
- Third-party API timeouts cascade into 500 errors
- Enable server error logging to identify exact failure points
- Use status checker to test during peak traffic hours—not just off-peak
- Increase PHP memory_limit, max_execution_time, and database connections
- Implement caching (Redis, Varnish) to reduce database load
- Add CDN to serve static assets—reduces server requests by 70-80%
- Monitor server resources and scale before hitting limits
Problem: SSL Certificate Expired/Invalid
Symptom: Browsers show "Your connection is not private" warning. Status checker reports SSL invalid. Visitors can't access your site.
- 95% of users leave immediately when seeing SSL warnings
- Google Chrome and Firefox block access by default—require clicking through warnings
- Search engines may deindex your site if certificate invalid for weeks
- Payment processors immediately fail on sites with SSL issues
- Use Let's Encrypt with auto-renewal—free certificates that refresh every 90 days automatically
- Set calendar reminders 30 days before expiration if using paid certificates
- Use our checker weekly to monitor SSL status and days until expiration
- Configure monitoring alerts when certificates have less than 30 days validity
- Test certificate renewal process in staging before running in production
Problem: Slow Response Times (> 2 seconds)
Symptom: Status checker shows 200 OK but response times are 2000-5000ms. Pages technically work but feel incredibly slow. Bounce rate increasing.
- Unoptimized database queries scanning millions of rows
- No page caching—regenerating HTML on every request
- Huge uncompressed images (5MB+ per page)
- Synchronous external API calls blocking page render
- Shared hosting plan oversold—competing for resources with 500 other sites
• Enable page caching
• Optimize database indexes
• Use CDN for assets
• Upgrade to better hosting
• Compress images (WebP format)
• Minify CSS/JS files
• Enable GZIP compression
• Lazy-load images
HTTP Status Monitoring Best Practices
Establish a Regular Checking Schedule
Reactive monitoring—checking only when problems surface—means you discover issues AFTER they've damaged your business. Proactive monitoring catches problems during deployment, before users report them. Set up a systematic schedule:
- Critical pages (homepage, checkout, login)
- Top 20 traffic-generating pages
- Customer-facing forms and applications
- API endpoints for mobile apps
- All indexed pages (from sitemap)
- Recent content additions
- Backlink destination URLs
- Third-party integration endpoints
- Immediately after deployments
- After DNS or hosting changes
- After SSL certificate renewals
- Post-redirect rule updates
Document and Track Findings
Don't just check status codes—maintain a record. This creates accountability, tracks improvement over time, and helps identify patterns. Use the CSV export feature to create a historical record:
Prioritize Issues by Business Impact
Not all HTTP errors are equally urgent. A 404 on an obscure blog post from 2015 matters less than a 500 error on your checkout page. Triage systematically:
Integration with Development Workflow
The best time to catch status code problems is during development, not after deployment to production. Build checking into your workflow:
- Test all new URLs in staging environment
- Verify redirect rules work correctly
- Check that old URLs still resolve properly
- Validate sitemap.xml contains only 200 OK URLs
- Smoke test critical paths immediately
- Bulk check all modified URLs within 1 hour
- Monitor error rates for 24-48 hours post-deploy
- Compare pre/post deployment response times
How HTTP Status Codes Directly Impact SEO Rankings
Search engines are sophisticated crawlers that navigate your website exactly like users—by following links and checking status codes. Google's algorithm interprets HTTP responses as quality signals. A site returning clean 200s signals professionalism and maintenance. A site riddled with 404s and 500s signals neglect. Here's precisely how status codes influence your search visibility:
200 OK: The Foundation of Good SEO
When Googlebot crawls a URL and receives 200 OK, it indexes the content, evaluates relevance, and assigns rankings. This is table stakes—without consistent 200 responses, you can't rank at all. But there are nuances:
- • Response time matters: Google's algorithm factors page speed. Pages loading under 1 second get preference over identical 3-second pages. Use our response time metrics to identify slow 200s.
- • Consistency matters: If a URL returns 200 OK one day, 500 the next, then 200 again, Google questions reliability and may rank it lower or crawl less frequently.
- • Mobile parity matters: Google uses mobile-first indexing. If desktop returns 200 but mobile returns 404 (or vice versa), rankings suffer from inconsistent signals.
301 Redirects: Preserve SEO Value During Changes
When you permanently move content, 301 redirects tell search engines "update your index to the new URL and transfer my rankings." Google passes approximately 90-95% of the original page's authority (PageRank) through 301s. This prevents ranking collapse during migrations.
- • Redirect to relevant content: Redirecting all deleted products to your homepage dilutes relevance. Redirect to similar products or the category page instead.
- • Keep redirects forever: Don't remove redirect rules after 6 months. Backlinks and bookmarks may reference old URLs for years. Permanent means permanent.
- • No redirect chains: Each hop in a chain loses ~10% authority. A 3-hop chain loses ~30%. Redirect directly to the final destination in one jump.
404 Errors: When They Help vs. Hurt SEO
Google explicitly states that "some 404 errors are normal and won't hurt your site." True—but context matters enormously. Here's when 404s damage rankings:
- • Previously indexed pages with rankings and backlinks
- • URLs in your sitemap.xml
- • Internal links pointing to non-existent pages
- • High-traffic pages that suddenly 404
- • 404 rates above 5-10% of crawled URLs
- • URLs that never existed (typos, guesses)
- • Spam URLs from bad bots
- • Intentionally deleted low-value content
- • Temporary test pages never meant to rank
- • Admin/login endpoints returning 404 to hide them
500 Errors: Critical SEO Emergencies
If Google encounters 500-series errors repeatedly, it assumes your site is broken and reduces crawl rate to avoid wasting resources. Sustained 500 errors for 24+ hours can trigger deindexing of affected URLs. This is catastrophic for rankings.
Frequently Asked Questions
How often should I check my website's HTTP status codes?
Critical pages: Daily. Your homepage, product pages, checkout, login—anything business-critical should be monitored every 24 hours. This catches problems immediately.
All indexed pages: Weekly. Extract URLs from your sitemap and run a bulk check every 7 days. This identifies broken links, new 404s, or performance degradation before they accumulate.
After changes: Immediately. Every deployment, DNS change, hosting migration, SSL renewal, or redirect rule update should trigger instant validation. Don't assume changes worked—verify.
What's the difference between 301 and 302 redirects?
301 Moved Permanently: The resource permanently moved to a new URL. Search engines update their index to the new location and transfer ~90-95% of SEO value (link equity, rankings). Use this for permanent changes: site migrations, URL structure changes, consolidated content.
302 Found (Temporary): The resource temporarily lives elsewhere but will return to the original URL. Search engines keep indexing the original URL and don't transfer rankings. Use this for A/B tests, temporary promotions, maintenance pages.
Critical mistake: Using 302 when you mean 301. If content permanently moved, always use 301. Many platforms default to 302, causing SEO disasters. Always verify with our checker.
Can too many HTTP requests hurt my website performance?
Yes, but our bulk checker is specifically designed to avoid this. We implement multiple protections:
- Rate limiting: Maximum 10 requests per second per domain by default
- Concurrency control: You choose simultaneous request limits (1-50)
- Request delays: 100ms delay between requests prevents server overwhelm
- Respectful checking: We send proper User-Agent headers and respect robots.txt
Best practice: If checking your own site on shared hosting, start with concurrency of 5-10. If checking robust servers or external domains, you can safely use 30-50 concurrency for faster results.
Why does my website show different status codes on mobile vs desktop?
Several reasons cause desktop/mobile status code discrepancies:
SEO impact: Google uses mobile-first indexing. If mobile returns 404 but desktop works, your rankings suffer. Test both versions or use tools that simulate mobile crawling.
How long should I keep redirect rules in place?
Permanent redirects (301): Forever. Never remove them. Here's why:
- Backlinks from other websites may reference old URLs for years or decades
- Users bookmark pages and return months/years later
- Old marketing materials, PDFs, printed documents contain old URLs
- Search engines may still have old URLs in their systems
- Email archives and social media posts link to old URLs permanently
Rule of thumb: Once you implement a 301 redirect, consider it permanent infrastructure. Redirect rules consume negligible server resources. The cost of removing them (lost traffic, broken links) far outweighs the cost of maintaining them (essentially zero).
What does "Too Many Redirects" error mean and how do I fix it?
This error occurs when browsers detect a redirect loop—URL A redirects to URL B, which redirects back to URL A, creating an infinite cycle. Browsers stop after 10-20 attempts and display "too many redirects" error.
- Conflicting redirect rules in .htaccess or nginx.conf
- Multiple WordPress plugins adding competing redirects
- SSL/HTTPS redirect loop (http → https → http → https)
- www/non-www redirect conflicts
- CloudFlare flexible SSL with server-side HTTPS redirects
- Use our checker with "Follow Redirects" enabled—it detects loops instantly
- Review all redirect rules in .htaccess, nginx config, and application code
- Disable redirect plugins one at a time to identify conflicts
- Check CloudFlare SSL settings (use "Full" not "Flexible")
- Clear browser cache and cookies after fixing—sometimes cached redirects persist
Should I use 404 or 410 Gone for deleted content?
Both tell users and search engines "this content doesn't exist," but they communicate different intentions:
Content doesn't exist, but might have never existed or could potentially return someday.
- URL never existed (typos, guesses)
- Content temporarily removed, might return
- Default for missing resources
Content deliberately deleted and will never return. Explicitly communicates finality.
- Discontinued products
- Expired promotions/events
- Deliberately removed content
- Want faster deindexing
How do I check if my SSL certificate is about to expire?
Our single URL checker automatically inspects SSL certificates when checking HTTPS URLs. After checking any https:// URL, scroll to the "SSL Certificate" section in results to see:
- Validity status: Whether the certificate is currently valid
- Days to expiry: How many days until expiration
- Issuer: Certificate authority (Let's Encrypt, DigiCert, etc.)
- Valid from/until dates: Exact validity period
Pro tip: Set up automated monitoring. Check your site weekly and configure alerts when SSL expiry drops below 30 days. This prevents the emergency scramble when certificates expire unexpectedly.
What's a good response time for my website?
Response time benchmarks depend on what you're measuring. Our checker reports Time to First Byte (TTFB)—how long until the server starts sending data. Here are industry standards:
Top-tier performance. Users perceive instant loading. Optimal for conversions and SEO.
Acceptable performance. Most users satisfied. No negative SEO impact.
Below average. Users notice slowness. Consider optimization. Slightly hurts SEO rankings.
Slow. High bounce rates likely. Needs immediate optimization. Significant SEO penalty.
Extremely slow. Users abandoning. Urgent optimization required. Severe SEO impact.
- • Static pages should be < 200ms with CDN
- • Dynamic pages (database queries) typically 200-500ms
- • E-commerce checkout may be 300-700ms due to payment processing
- • API endpoints should be < 100ms for good user experience
Start Monitoring Your Website Health Today
Don't wait for users to report broken links or for search rankings to drop. Proactive HTTP status monitoring prevents problems before they cost you traffic and revenue.
No registration required • Check up to 500 URLs • Export results to CSV