Meta description length: 100 to 160 and why the cut hurts

The meta description is the sales copy under your ranking. Google truncates it around 160 characters on desktop and sooner on mobile and swaps it entirely when it judges yours irrelevant to the query. The working range: 100 to 160 characters, one complete thought, cut nowhere.

What the description actually does

It does not affect ranking directly. It affects the click and the click affects everything: a page seen often and chosen rarely is how positions decay. Two pages at the same spot can differ several-fold in clicks purely on snippet quality, which compounds into their future positions.

The failure modes

• Over 160: the sentence dies mid-thought in the results. A cut snippet reads as carelessness and the click goes to the next result.
• Under 100: the space under your title renders thin against competitors using theirs fully.
• Missing: Google assembles one from page fragments, mid-sentence, out of context.
• Keyword-stuffed: triggers the swap. Google replaces descriptions that read as tag soup.

Writing one that earns the click

1. Answer what the page delivers for the query, in the searcher's vocabulary. Their query terms render in bold in the snippet, which is free emphasis.
2. Include one specific: a number, a range, a named outcome. Specifics separate you from the template descriptions around you.
3. End complete. If it cannot fit whole under 160, it is two thoughts, cut one.