International SEO
Locale-Adaptive Tester
See how language preference headers affect the response your server returns.
- Fetched live by our server
- Nothing stored
The tool
Enter a public URL and language preferences. This tests request headers, not physical location.
Loading the tool…
The URL you enter is sent to our server, which requests that page from the public internet and returns the response to your browser for analysis. We do not store the URL or the response, and we do not add either to analytics. Requests come from our server, not from your device or from the crawlers being simulated, so a site that blocks data-centre addresses or verifies crawlers by IP may answer differently.
What this tool checks
- HTTP response and final URL for each language header
- HTML lang, canonical, title, description, headings, and representative text
- Material response differences by request preference
How to read the results
- Enter a public page URL.
- Add up to four Accept-Language values, one per line.
- Compare response evidence and repeat with the same inputs to reproduce the request.
About this tool
What this tester compares
The tester sends the same public URL with different Accept-Language request headers, then compares status, final URL, page language, canonical, title, description, headings, and a short text sample.
Header simulation is not geolocation
All requests originate from the same server location. The test does not change IP geography, cookies, account state, or browser locale. A different response indicates header-sensitive behavior only.
How to use the findings
Confirm that each response is intentional, has a suitable language declaration and canonical, and does not unexpectedly redirect users or crawlers. Consider caching behavior when your server varies responses by request headers.
Limits and honest caveats
- Requests originate from this web server; no country-specific proxy or geolocation is used.
- Accept-Language is only a preference signal and does not prove what a visitor in a country receives.
- JavaScript is not executed; use Fetch & Render when client-side rendering changes the content.
What people use it for
- Check Accept-Language redirects
- Verify language-specific metadata and HTML lang
- Investigate cache variation for multilingual pages
Questions
Questions about this tool
The things clients actually want to know — costs, timelines, ownership and what happens after launch.
No. It varies only the Accept-Language header from this server.
No. It compares fetched HTML. Use Fetch & Render for browser-rendered output.
Documentation last reviewed: by the Best Web Developer engineering team.
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- Working since
- 2023