Mobile-First Index Checker
Fetch a live URL as Googlebot Smartphone and Googlebot Desktop and diff what each sees — title, meta description, robots, canonical, h1s, structured data, hreflang, and word count — to catch mobile-first indexing parity gaps before Google does.
Input
Fetched twice server-side — once as Googlebot Smartphone, once as Googlebot Desktop.
Output
| Severity | Field | Issue |
|---|---|---|
| No data yet | ||
| Field | Mobile (Googlebot) | Desktop (Googlebot) | Match |
|---|---|---|---|
| No data yet | |||
Guides
What the Mobile-First Index Checker does
Enter a live URL and this tool fetches it twice server-side — once with Google's real Googlebot Smartphone user agent, once with Googlebot Desktop — and diffs what each version returns: title tag, meta description, robots directive, canonical URL, h1 headings, schema.org structured data, hreflang tags, and an approximate word count. Google indexes almost every site using its mobile crawler today, so anything missing, thinner, or contradictory on the mobile response simply doesn't make it into the index — even if the desktop page has it.
How to use it
- Enter the full URL of the page you want to audit.
- Click Compare mobile vs desktop. The page is fetched twice server-side (cross-origin HTML can't be read from the browser, and spoofing a crawler's User-Agent isn't something client-side JavaScript can do).
- Review the Parity issues table for anything to fix, and the Mobile vs. desktop table for the full side-by-side comparison.
What gets flagged
- Title, meta robots, canonical URL (error) — these directly control what gets indexed and under what URL. A mismatch here is the most consequential kind of parity gap.
- Meta description, h1 content, structured data types (warning) — these shape how the indexed page is understood and displayed, not whether it's indexed at all.
- hreflang count, image count, word count (info/warning) — secondary signals; a large word-count gap (>15%) is flagged as a warning since it often means the mobile version is missing content sections a desktop-only template still renders.
Why this happens
Most modern responsive sites serve byte-identical HTML regardless of User-Agent — content is reflowed with CSS, not swapped server-side — so a parity gap on a responsive site usually means "no issues found." The gaps this tool catches show up on sites still doing UA-sniffing or adaptive serving (a separate mobile theme, an m. subdomain, a CMS plugin that trims content "for mobile performance"): exactly the setups mobile-first indexing quietly penalizes, because Google never sees the desktop version at all.
Scope
Both fetches read the raw HTML response — there's no headless browser rendering either side, so JavaScript-injected content that differs between mobile and desktop after the initial HTML load won't show up here. For that, check the page's client-side rendering behavior separately.
Privacy
The URL is fetched by our server only to compare the two responses and isn't stored. Requests to private or local network addresses are blocked.
Use it from code
From 3 credits per callREST API
curl -X POST https://api.iotools.cloud/v1/tool/mobile-first-index-checker \
-H "Authorization: Bearer YOUR_API_KEY" \
-H "Content-Type: application/json" \
-d '{
"url": "https://example.com/"
}'Swap in your own key from your account. The tool's fields are the body — no wrapper.
Ask an AI agent
Use the IOTools `mobile-first-index-checker` tool (Mobile-First Index Checker) on this input:
YOUR_INPUT_HEREPaste this at any agent connected to the IOTools MCP server, then add your input.