Free SEO checker: the on-page issues that actually move rankings
On-page SEO is a small number of things done consistently. Here is the short list that accounts for most of what an audit finds, in the order worth fixing it.
By Sapun Lamichhane · Arcetis
On-page SEO has a long tail of refinements and a short head of things that genuinely matter. Most audits bury the second in the first. This is the short list, ordered so that the expensive work comes after the cheap work that makes it worthwhile.
First: is the page indexable at all?
Everything else is irrelevant if the answer is no, and a surprising number of audits report on titles and headings for pages carrying a noindex tag.
- No robots meta tag set to noindex. The single most expensive line a site ships by accident, usually left over from staging.
- Not disallowed in robots.txt.
- A canonical that points at itself, or at the version you actually want indexed.
- Linked from somewhere in your own navigation. An orphan page is one a crawler has no path to.
Second: is each page distinguishable?
Titles and meta descriptions are what a result is assembled from, and duplicates across templated pages are the most common serious on-page problem there is. The failure mode is not that a duplicate ranks badly — it is that two of your own pages compete for the same query and neither wins.
One h1 per page, describing that page rather than the site. Headings in order, without skipping levels, because the hierarchy is how both a crawler and a screen reader understand the document's shape.
Third: the things that quietly cost you
- Missing image alt text — an accessibility failure first and an SEO one second.
- Broken internal links, which waste crawl budget and break the path authority flows along.
- Missing viewport meta tag, which makes the mobile version — the version being indexed — unusable.
- Slow LCP, which is both a ranking factor and the reason a visitor leaves before your content renders.
What has changed, and what has not
The fundamentals above have been stable for a decade and remain the bulk of the work. What has changed is that the same page now has a second audience: assistants that quote rather than rank.
The good news is that the foundations serve both. Clean structure, fast pages and accurate markup help a crawler and an answer engine equally. The divergence is at the margin — ranking rewards depth and authority, quoting rewards a bounded, self-contained answer — and it is worth writing for the second deliberately once the first is in order.
What free means here
Our SEO checker is free, with no account for your first full scan and unlimited quick scans. Every finding names its rule, quotes the evidence from your page, and links to the specification behind it — which is the difference between an audit you can act on and a number you have to believe.