Google snippet preview: how your article looks in search
Type a title, a description and an address, and you see the same card a reader meets in search results: the address, the blue title, the grey description and the date. You can tell at once whether the title fits and exactly where it gets cut. This is the first thing that sells your text. A person reads a snippet in half a second and decides whether to click or scroll on. For a new author that matters more than any other optimisation: without the click there is no read, no client and no subscriber.
What goes into the results page
What the reader will see
Your text never leaves the browser: width is measured with a built-in table of letter widths, with no network calls.
Google rewrites titles very often and almost always builds the description from the page text itself. This tool shows the truncation limits, not a guarantee of what the user will see.
Why pixels and not characters
Google does not cut the title after a fixed number of letters. It cuts when the line stops fitting into the width it is given. That is why "Illinois" and "wwwwwwww" are the same length and completely different widths: the first word has narrow letters, the second has the widest letter in the Latin alphabet eight times over. The tool has a built-in table of Arial letter widths: Latin, Cyrillic, digits and common punctuation. Every character's width is known in thousandths of the font size, so the title is measured at 20 px, the description at 14 px, and the sum is compared with the device limit. An unknown character gets the width of the letter "o", 0.556 of the font size. The reference points: on desktop a title fits up to roughly 600 px and a description up to 920 px. On mobile a title can take up to 920 px because it wraps onto two lines, and a description up to 1030 px. These are settled industry numbers measured against real search results, not an official standard: Google has never published figures like these.
How to write a title that does not get cut
Put the most important part first. If the title does get cut, it is the end that disappears, and the end should hold neither the key phrase, nor the main promise, nor the number. Add the site name at the end after a dash or a pipe, and only if there is room left. Repeating it in every title serves no purpose: the reader already sees the domain on the line above. The description is not a restatement of the title. The title names the topic; the description answers the question "what do I get out of this": specifics, numbers, who the text is for. When both lines are built from the same words, the reader gets one thought twice and learns nothing new. The tool flags repetitions like that separately.
What this tool does not do
It does not promise that Google will show your text. By various estimates the search engine rewrites titles in about half of all cases, and it builds the description from the page text even more often — particularly when the query is narrow and the page has a more precise sentence in it. It does not check the page over the network: nothing is downloaded and nothing is sent. You type the text by hand and all the counting happens in your browser. It does not show snippet extensions — rating stars, prices, breadcrumbs from structured data, a thumbnail alongside. Those depend on your structured data and on Google's own decision. And it does not judge the quality of your writing. A title can fit into 600 px perfectly and still interest nobody.
A quick check before publishing
The key phrase sits in the first three words of the title. The title does not turn red in the preview, meaning it fits in full. The description contains the same phrase, used once and naturally. The description is longer than 60 characters, otherwise Google will almost certainly replace it with its own snippet. The description does not repeat the title word for word. The address is short and readable — a long tail of random digits looks suspicious in search results. And one more thing: switch the device to mobile. Most of your readers will see the snippet there, and the mobile limits are different.