When the URL Checker runs, it generates a spreadsheet with multiple tabs that sort your landing pages by what the tool found. This article explains what each tab means and how to read the HTTP response codes that appear in your results.
Spreadsheet Tabs
Each tab groups your URLs by what the checker found during that run. A URL will only appear in one tab per run, based on the response the server returned or whether a response was received at all.
404 Error
A 404 error means the page the URL Checker tried to access couldn't be found or doesn't exist. This is usually caused by a mistake in the Final URL, or a page that has been moved or deleted.
Note: you don't need to add "404" as a Text to Monitor keyword. The tool detects 404 responses automatically via HTTP status codes and logs them here.
No Issues
URLs that returned a 200 or 202 response and had no matches in your Text to Monitor field.
A 200 ("OK") means the request was successful and the server returned the expected content.
A 202 ("Accepted") means the server received the request but hasn't finished processing it yet.
LP Content Warnings
URLs that returned a 200 or 202 response and had at least one match from your Text to Monitor field.
The URL Checker fetches the full raw HTML source of the page and searches for your keywords anywhere in that source — including JavaScript bundles, translation files, and app data embedded in the page. This means the search is not limited to text that a real visitor would see.
Short or common phrases like "not found", "out of stock", or "error" may appear in the page's source code as translation keys or UI state labels, even on pages that are working fine. If you're seeing unexpected flags here, consider using code snippets that indicate that something is wrong with your landing page or longer and more specific phrases.
Not Checked
URLs in this tab didn't return any HTTP response at all. The tool wasn't able to determine whether these pages are working or not.
This happens when:
The request times out — the checker has a 6-second limit per URL
The connection fails before any response is returned
The same domain has failed 3 times in a row — in that case, remaining URLs on that domain are skipped for the rest of that run
Not Checked means the page was unreachable during that run, not that it's confirmed broken.
Checked
All URLs that were checked and returned any HTTP response code, regardless of what that code was.
Other Responses
URLs that returned response codes other than 200, 202, or 404. Common ones include:
403 (Forbidden) — the server is refusing access or blocking the URL Checker. The tool won't be able to crawl the page or detect issues as intended. To resolve this, you can whitelist the Optmyzr user agent
Optmyzrbot/1.0.0in your firewall or CDN settings.500 (Internal Server Error) — the page couldn't be accessed or crawled properly. The URL Checker won't be able to detect error codes or monitor text on these pages.
502 (Bad Gateway) — the server's gateway couldn't reach the origin at that moment. This is almost always temporary, caused by a brief server overload, a deployment in progress, or the site's firewall blocking the request. If the URL works fine when you check it manually, re-running the checker should return a clean result.
429 (Too Many Requests) — the server rate-limited the checker due to too many requests in a short period. To prevent this, whitelist
Optmyzrbot/1.0.0in your firewall service.
Special Responses
URLs that returned one of the HTTP status codes you specified in the Check for special response codes setting. These are codes you've chosen to monitor separately — for example, 301 or 302 redirects — that wouldn't otherwise be flagged as errors.
Note: if you add a 3xx code to your special response codes list, it also changes how the checker handles redirect-following for that run. See the URL Checker User Guide for more on configuring this setting.
Actions
If you run the automation in Apply mode, this tab acts as a log of all changes the URL Checker applied to your account — such as paused keywords or ads.
Understanding HTTP response codes
HTTP response codes are the server's way of telling the checker what happened when it tried to access a page. Here's what each range means and which codes you're most likely to see in your results.
1xx — Informational
Informational responses. These are rarely seen in URL Checker results.
2xx — Success
The page was reached successfully.
200 (OK) — the request was successful and the server returned the expected content.
202 (Accepted) — the server received the request but hasn't finished processing it yet.
3xx — Redirects
The URL points to a new location. These codes are generated when an old URL redirects to a new one. In some cases this can slow down page load speed and affect user experience.
301 (Moved Permanently) — the page has permanently moved to a new URL.
302 (Found) — the page has temporarily moved to a new URL.
By default, the checker follows the redirect and reports on the final destination page. To flag redirecting URLs separately, add 301 or 302 to your Check for special response codes setting.
4xx — Client-side errors
These are generated when your landing page is not loading and there may be something broken. Common causes include a change in domain name, a broken URL, or restricted access.
400 (Bad Request) — the server couldn't process the request.
401 (Unauthorized) — the page requires valid authentication credentials.
403 (Forbidden) — the server is refusing access. This may mean the URL Checker is being blocked. To resolve this, whitelist
Optmyzrbot/1.0.0in your firewall or CDN settings.404 (Not Found) — the page doesn't exist or has been removed.
410 (Gone) — similar to 404, but confirms the page has been permanently removed.
429 (Too Many Requests) — the server rate-limited the checker. To prevent this, whitelist
Optmyzrbot/1.0.0in your firewall service.
5xx — Server-side errors
These are generated due to issues on the backend of your website and are also called server-side errors.
500 (Internal Server Error) — the page couldn't be accessed or crawled properly. The URL Checker won't be able to detect error codes or monitor text on these pages.
502 (Bad Gateway) — the server's gateway couldn't reach the origin at that moment. This is almost always temporary, caused by a brief server overload, a deployment in progress, or the site's firewall blocking the request. If the URL works fine when you open it manually, re-running the checker should return a clean result.
503 (Service Unavailable) — the server is temporarily unable to handle the request.
504 (Gateway Timeout) — the server took too long to respond.