When a site doesn't show on Google it is almost always one of seven causes, and they are worth checking in a fixed order, because the first three take minutes to rule out. There are also three different problems that get mixed up: the site isn't in Google at all, it is in Google but ranks too low to be seen, or it used to be visible and has slipped. The fix is different for each.
First: is the site in Google at all?
Search for site:yourdomain.com on Google. If pages appear, your site is indexed and your problem is ranking, not indexing, so skip to cause five. If nothing appears, the problem is one of the first four causes.
The seven causes, in order
- The site is new. Google can take days or weeks to index a new site. Speed it up: verify the site in Google Search Console and submit a sitemap. That is the single most effective step for a new site.
- Something tells Google to stay away. A leftover noindex tag or a robots.txt block from the development phase is a classic. View the page source and search for "noindex", and check yourdomain.com/robots.txt.
- No sitemap and no internal links. Google finds pages by following links. Pages that nothing links to may never be found. A sitemap fixes this in one file.
- Technical failure. If the server is slow, the page errors out, or the domain recently moved without redirects, indexing stalls. Search Console's page report says exactly which pages failed and why.
- The pages don't answer what people search for. The most common cause of all. A title like "Home | Company AB" tells Google nothing. A page about bathroom renovation that never uses words a customer would type will not show for those searches.
- You show up, just too far down. Position 40 is technically "showing on Google" and practically invisible. This is a competition problem: stronger pages answer the same search better.
- You used to be visible and slipped. Pages age. Competitors publish newer answers, search intent moves, and a page that ranked for years fades month by month. This one is sneaky because nothing looks broken.
"Showing" is not a yes/no question
Google Search Console separates impressions (how often you appeared in results) from clicks. A page can have thousands of impressions and no clicks: visible in theory, invisible in practice. That is why "does my site show on Google" is really three questions: are we indexed, where do we appear, and does anyone click.
See exactly what Google shows today
Connect your site to Google Search Console (free, run by Google). The performance report lists every search your pages appeared for, with position and clicks per page. Read it monthly and cause seven never sneaks up on you.