Hreflang Uses Relative URL
Hreflang requires absolute URLs.
Why it matters
Hreflang requires absolute URLs. Relative URLs are ignored, breaking multilingual targeting.
Schedule a fix in your next sprint. Warnings won't block your site but they consistently leave performance on the table. Estimated SEO impact: medium — measurable effect on click-through or relevance.
How to fix
- Replace relative hrefs with absolute ones (https://example.com/fr/page)
- Use your domain as the base for every hreflang
Common causes
If the rule is firing across many pages, the root cause is almost always one of these:
noindexapplied broadly during a redesign and never removed for live pages.- Robots.txt blocks a path that contains canonical pages along with the unwanted ones.
- CMS publishes a draft URL with a self-referential canonical pointing to a different slug.
- Tracking-parameter URLs proliferate and dilute crawl budget.
Anti-patterns to avoid
Even with the best intentions, these "fixes" make the issue worse — recognise them so you don't ship them:
noindexapplied to a directory that also holds canonical pages.- Self-canonical pointing at a redirect chain.
- Robots.txt disallowing paths Google needs to render the page.
How atlookup detects this
Our crawler renders each page with a real headless browser, then reads robots directives, canonical tags, sitemap entries, and tests fetchability. Pages where the rule fires for hreflang uses relative url are flagged on the report.
If you'd like to see this rule fire on your own site, run a free 60-second audit — every page is reported with the exact lines that triggered it.
Tools to verify the fix
Once you've applied the fix, double-check with these external validators:
- Google Search Console — URL Inspection shows exactly how Google treats the page.
- robots.txt Tester — Live test of disallow rules against your URLs.
Frequently asked questions
Why does Hreflang Uses Relative URL matter for SEO?
Hreflang requires absolute URLs. Relative URLs are ignored, breaking multilingual targeting.
How do I fix hreflang uses relative url?
Replace relative hrefs with absolute ones (https://example.com/fr/page) Use your domain as the base for every hreflang
Is this a critical SEO issue?
Schedule a fix in your next sprint. Warnings won't block your site but they consistently leave performance on the table. Estimated SEO impact: medium — measurable effect on click-through or relevance.
How does atlookup detect hreflang uses relative url?
Our crawler renders each page with a real headless browser, then reads robots directives, canonical tags, sitemap entries, and tests fetchability. Pages where the rule fires for hreflang uses relative url are flagged on the report.
How long does it take to fix?
5–15 minutes per page. Most teams batch similar issues across templates so the per-page time goes down at scale.
Related issues
CANONICAL_EMPTY
Empty Canonical Tag
An empty <link rel="canonical" href=""> canonicalizes to the current URL in some crawlers and nothing in others — unpredictable behavior that often leads to deindexing.
CANONICAL_INVALID
Invalid Canonical URL
A canonical URL that fails URL parsing (e.g.
ROBOTS_TXT_BLOCKS_INDEXABLE_PAGE
Robots.txt Blocks an Otherwise-Indexable Page
When robots.txt disallows a URL that returns 200 + meta robots index + canonical-to-self, you have a direct contradiction in indexing signals.
SITEMAP_URL_4XX
Sitemap URL Returns 4xx
A URL listed in your sitemap but returning 4xx (typically 404) tells Google that page should be indexed, then fails when crawled — a strong negative signal about site maintenance.