What this SERP snippet preview does
Paste a title, a meta description and the page address, and this SERP snippet preview draws the Google result twice: once at desktop width and once as a phone shows it. Each field is measured in pixels against the budget that device really has, the address becomes the breadcrumb trail Google prints in place of a URL, and the text is cut at the word where it would actually stop.
Pixels are the unit, characters are the folklore
Search results are text laid out in a proportional typeface. Google draws the blue link at around 20px and the grey description at around 14px, and every glyph in those lines has its own advance width. A capital W occupies 944 units of a 1000-unit em; a lowercase l occupies 222. So a title of sixty capitals is a completely different object from a title of sixty lowercase letters, and the famous sixty-character limit describes only the middle of that range.
The practical budgets are about 600px for the desktop title and about 920px for the two-line desktop description. A phone is narrower, which makes people assume it is stricter — it is not. Mobile results wrap over more lines, so the total text that survives is larger, not smaller. If a line has to be sacrificed somewhere, sacrifice it on the phone and write to the desktop number.
This tool estimates width from published Arial advance widths rather than from a hidden canvas element, so the numbers are identical in the test suite and in your browser. What it cannot model is kerning between specific letter pairs, the substitute font a device picks for an emoji or a non-Latin script, and the fact that Google does not use Arial everywhere. Near the limit, treat the verdict as a probability rather than a fact.
Your title is a strong suggestion
Since 2021, Google replaces the title it displays whenever the tag looks unsuited to the query. It prefers your tag most of the time, and the exceptions are predictable: repeated keywords, a template that produces the same line on a thousand pages, shouting in capitals, or a tag shorter and vaguer than the H1 sitting under it. The replacement is drawn from the H1, from anchor text, or from the site name glued to the heading.
Descriptions are rewritten far more often than titles, and that is not a failure. Google assembles a passage around the words someone typed, which frequently serves the searcher better than a sentence written months earlier. Write the description for the query you most want, accept that long-tail visitors will see something else, and never leave it empty in the hope of getting lucky.
Dates, breadcrumbs and the rest of the line
Two more elements share the space. The breadcrumb replaced the raw URL in 2020: Google shows the
domain without www. followed by path segments, which is why a long, readable slug now reads as
part of the result rather than as noise. And a date prefix appears on anything Google treats as time
sensitive, silently taking around 95px off the description before your first word is drawn.
Once the wording holds up here, the meta tag generator writes the tags, the meta tag analyzer confirms what a page already ships, and the SEO word counter covers the body copy the snippet is promising.