Locale-Adaptive Tester
Free tool · International SEO check
Locale-adaptive tester
Test how your webpage responds to different language settings. Enter an address and the tool requests it with five different Accept-Language headers (US English, Australian English, German, French, and Japanese) and compares what comes back.
What Is a Locale Adaptive Tester?
A Locale Adaptive Tester checks how a webpage responds when requested with different language settings.
It requests the same address 5 times with a different Accept-Language header each time, en-US, en-AU, de-DE, fr-FR, and ja-JP, and compares the response status, declared page language, title, and content size across all 5.
What This Locale Adaptive Tester Checks
- Language adaptation: Checks whether the response status, title, declared page language, or content size changes based on the Accept-Language header.
- Content differences: Flags a difference in content size as a sign the page content itself changed.
- Same-URL behavior: Since the address tested never changes, shows whether locale-based content is served without a separate URL for each locale.
What This Locale Adaptive Tester Does Not Check
- Does not simulate country, IP, or geolocation, only the Accept-Language header
- Does not test locales beyond the fixed 5: en-US, en-AU, de-DE, fr-FR, and ja-JP
- Does not detect or follow locale-triggered redirects; it follows redirects silently and compares the final response
- Does not guarantee how every search engine crawler will experience the page
- Does not automatically fix locale-based behavior
- Does not translate your website content
- Does not replace a complete international SEO audit
Why Test Locale-Adaptive Websites?
Locale-based personalization can create different experiences for users in different language groups, even at the same URL.
Googlebot crawls almost entirely from the United States with English headers. If a page only changes for other Accept-Language values, that content may never get crawled or indexed at all.
Use the tester to:
- Check whether a page adapts content based on browser language alone
- Find content that only appears for non-English Accept-Language headers
- Confirm a page serves the same content regardless of language setting
- Decide whether locale-specific content needs its own URL
- Troubleshoot inconsistent language-based experiences
How to Test Locale Adaptation
- Enter the address you want to test.
- Run the test. The tool requests that one address 5 times, once per Accept-Language header.
- Review the result: whether the status, title, declared language, and content size stayed the same across all 5, or which ones changed.
- If content changes without the URL changing, give each locale that matters its own URL so crawlers using different headers can reach it.
Frequently Asked Questions
What is a Locale Adaptive Tester?
A Locale Adaptive Tester checks how a webpage responds to different Accept-Language browser settings, without changing the URL being tested.
What is locale-based content?
Locale-based content is webpage content that changes according to a visitor's language setting, even when the address stays the same.
Does locale adaptation affect SEO?
It can. Googlebot crawls mostly with US English headers, so content that only appears for other Accept-Language values may never get crawled or indexed.
Can I test different countries or IP locations with this tool?
No. This tool only varies the Accept-Language header; it does not simulate a visitor's country or IP address.
Does this tool replace a hreflang checker?
No. This tool checks how a single URL behaves under different language headers, while a hreflang checker analyzes the hreflang implementation between separate localized URLs.