ads.txt monitor

If a line disappears from your ads.txt, the exchange it authorised stops bidding on your inventory — usually within hours, and with no warning in any dashboard you already check. Monetific watches the file continuously and emails you the specific line that changed.

How it works

1. Add your domain. Enter the site you want watched. No code, no DNS change, no plugin.
2. Baseline the file. Monetific reads your current ads.txt and records every line as required. That baseline is what future checks are measured against.
3. Get alerted. When a required line disappears, the file stops resolving, or your host starts serving an HTML page instead of plain text, you get an email naming the exact line and what changed.

What it catches

• Missing required entries — the line you depend on is gone, everything else looks fine.
• 404 and 5xx responses — the file is not there at all.
• HTML served as ads.txt — HTTP 200, styled error page, zero valid records. The quiet killer.
• Syntax errors — a malformed relationship field or a missing comma invalidates the line, and the report names the line number.
• Unexpected additions — a reseller line you did not add, which is worth knowing about for its own reasons.

Frequently asked

What actually happens when ads.txt breaks?

Exchanges re-crawl ads.txt regularly. If a seller's line is missing, that exchange treats your inventory as unauthorised and stops bidding on it. Fill rate and RPM fall within hours. Neither AdSense nor your ad manager raises an alarm — the numbers simply come in lower.

What breaks an ads.txt in practice?

A theme or plugin update overwriting the file, a host serving a styled 404 page with an HTTP 200 status, a CDN rule intercepting the path, a network switch that removed old lines before the new ones went live, and an agency editing the file without telling the owner. All of them are silent.

How often is the file checked?

Every 24 hours on the free plan, every 6 hours on Starter, hourly on Pro and every 15 minutes on Agency. Frequency is the product: the loss is proportional to how long the breakage lasts.

Why does an HTML page with a 200 status matter?

Because a naive check sees HTTP 200 and reports success. Exchanges parse the body, find no valid records, and treat the file as absent. It is the failure mode most likely to go unnoticed for weeks, which is why Monetific checks the content type and the body shape rather than just the status code.