About SERP Preview
A search result gives you two lines to win a click against nine competitors. Seeing it rendered before you publish is the difference between a title that reads well and one that ends mid-word in an ellipsis.
Almost every preview tool measures characters, and Google does not. It truncates when the rendered text passes a pixel width — roughly 580 pixels for a desktop title. Characters differ enormously in width: a capital W is more than four times as wide as a lowercase l, so two 60-character titles can have wildly different fates. This preview uses the Arial metrics Google renders results in, which is why its cut-off point often differs from tools that count characters.
Mobile is shown alongside desktop because the column is narrower there and most searches happen on phones. A title that fits comfortably on a laptop is frequently clipped on the device most of your visitors are using.
How to preview your search result
Enter your title, URL and description
Use the exact text from your page's tags, not an approximation.
Compare desktop and mobile
Check both. The mobile column is narrower and is where most of your traffic will see you.
Move the important words forward
If the end is cut, rewrite so the words people searched for appear early rather than trimming from the middle.