HTTP status codes → communicate → a page’s accessibility and state to search engines.
When Googlebot or a browser requests a URL, your server responds with a code that tells it what happened — whether the page loaded successfully, redirected, or failed.
Understanding these codes is essential for diagnosing crawl errors, fixing visibility issues, and maintaining a healthy, indexable website.
In this guide by Kasra Dash, we’ll explain what HTTP status codes are, how they affect SEO, and how to fix common errors that waste crawl budget or block indexing.
→ Before you begin, revisit Technical SEO and Fix Indexing Issues to understand how crawlability and accessibility work together.
HTTP status codes are the language of communication between your website and search engines.
What Are HTTP Status Codes?
HTTP status codes → indicate → the result of a request between a browser (client) and a web server.
They are three-digit responses that tell search engines whether a page is available, redirected, missing, or broken.
Each code belongs to one of five main classes:
| Class | Range | Type | Description |
|---|---|---|---|
| 1xx | 100–199 | Informational | Request received, still processing. |
| 2xx | 200–299 | Success | Page loaded correctly. |
| 3xx | 300–399 | Redirects | Page has moved. |
| 4xx | 400–499 | Client errors | Page not found or request invalid. |
| 5xx | 500–599 | Server errors | Server failed to complete request. |
Status codes → influence → how search engines crawl and index your site.
→ Learn how these responses shape visibility in Google Crawling & Indexing.
Every code tells Google whether to keep, update, or drop a page from the index.
SEO Impact of HTTP Status Codes
Your server’s responses determine whether Googlebot can access and index content successfully.
Let’s break down the most common HTTP codes and their SEO implications.
✅ 200 OK — Success
The page loads correctly. This is the ideal response for all indexable pages.
🔁 301 Moved Permanently
Signals that a page has permanently moved to a new URL.
- Passes around 90–99% of link equity.
- Google transfers ranking signals to the new page.
- Should always be used for permanent redirects.
→ Compare with canonicalisation in Canonical Tags.
⚠️ 302 Found (Temporary Redirect)
Indicates a temporary move.
- Does not pass full link equity.
- Use only when the redirect is short-term (e.g., testing).
❌ 404 Not Found
The server can’t find the requested page.
- Temporary 404s may be crawled again later.
- Persistent 404s waste crawl budget and harm UX.
- Fix by redirecting, restoring, or removing from sitemap.
→ Diagnose visibility loss via Fix Indexing Issues.
🚫 410 Gone
Informs Google the page is permanently removed.
- Faster deindexation than a 404.
- Useful for content you never plan to restore.
💥 500 Internal Server Error
Occurs when the server fails to process a request.
- Stops crawling immediately.
- May cause deindexing if persistent.
- Investigate via server logs or hosting support.
→ Monitor crawl frequency and wasted resources in Crawl Budget.
🧱 503 Service Unavailable
Used during maintenance or downtime.
- Temporarily tells bots to retry later.
- Safe if resolved quickly.
Correct HTTP codes tell Google what to keep; incorrect ones make it guess.
Can HTTP errors affect my SEO rankings?
Yes — persistent 4xx or 5xx errors can remove pages from Google’s index, reduce crawl frequency, and damage site trust signals.
Common SEO Problems from HTTP Codes
Misconfigured responses can confuse crawlers, leading to lost rankings and crawl inefficiency.
1. Redirect Loops
When pages redirect in circles (A → B → A), Googlebot stops following them, wasting crawl budget.
2. Broken Internal Links
Links to deleted or renamed pages trigger 404s, damaging UX and link equity.
3. Soft 404s
Pages return a 200 OK status but display “not found” content — confusing for crawlers and users alike.
4. Server Failures
Frequent 500 errors indicate server instability or resource overload.
→ Identify these issues with a Technical SEO Audit and review canonical logic in Canonical Tags.
Every incorrect status code creates friction between your site and Googlebot.
How can I spot redirect loops?
Run a site crawl with Screaming Frog or Ahrefs Site Audit and check redirect chains. Loops will appear as repeated destination URLs.
Fixing HTTP Errors
Step 1: Fix 404 & 410 Errors
- Restore deleted pages if they still attract traffic.
- Redirect removed URLs to the most relevant page.
- Remove obsolete URLs from XML sitemaps.
Step 2: Clean Up Redirects
- Replace 302s with 301s for permanent changes.
- Avoid chains (301 → 301 → 301).
- Use direct redirects instead.
Step 3: Resolve 500 Errors
- Check server logs and error reports.
- Upgrade hosting or caching configuration.
- Review scripts causing high CPU load.
Step 4: Monitor 503s and Downtime
- Implement caching and load balancing.
- Use a 503 + Retry-After header during planned maintenance.
→ Address persistent errors in Fix Indexing Issues and track crawl patterns in Crawl Budget.
Every fixed error restores both user trust and crawl equity.
Should I redirect all 404s to my homepage?
No. That confuses users and Google. Always redirect to the most contextually relevant page or let genuine 404s stand if content is gone.
Redirects vs Canonicals
Both 301 redirects and canonical tags help manage duplication — but they serve different purposes.
| Aspect | 301 Redirect | Canonical Tag |
|---|---|---|
| Function | Moves users and bots permanently | Consolidates duplicate pages without redirecting |
| User Impact | Redirects visitors to new URL | Keeps users on current page |
| Link Equity | Passes nearly all | Consolidates signals |
| Use When | Content is moved or merged | Variants exist (UTMs, filters, pagination) |
→ Learn deeper duplication strategies in Canonical Tags.
Redirects tell Google where content moved; canonicals tell it which version to prefer.
Testing and Monitoring
Proactive monitoring ensures that your server consistently returns correct codes.
Recommended Tools
| Tool | Purpose |
|---|---|
| Google Search Console | Check Indexing → “Pages” report for 404s, redirects, and soft errors. |
| Screaming Frog / Sitebulb | Crawl your site for response code anomalies. |
| cURL | Manually check HTTP headers from terminal. |
| Ahrefs Site Audit | Identify 3xx and 4xx chains. |
Monitoring Tips
- Crawl your site monthly.
- Audit new URLs after site migrations.
- Log and track server response trends.
- Check canonical and redirect behaviour after CMS updates.
→ Incorporate these checks into your Technical SEO Audit for continuous health tracking.
Monitoring ensures your site speaks clearly to both users and crawlers.
How do I test a single URL’s status code?
Use a terminal command:
curl -I https://example.com/The first line (e.g., HTTP/2 200) shows the status code.
Summary: HTTP Status Codes Define Visibility
HTTP status codes tell search engines what’s working, what’s missing, and what’s broken.
To recap:
- 200 = Healthy, indexable page.
- 301 = Permanent redirect (good).
- 302 = Temporary redirect (use sparingly).
- 404 / 410 = Missing or removed content.
- 500 / 503 = Server problems.
→ Run a Technical SEO Audit to uncover 404s, broken redirects, and crawl errors before they impact rankings.
HTTP codes are your website’s heartbeat — consistent, healthy responses mean stronger visibility.
