The ideal meta description length is 150–160 characters, with 155 being the sweet spot that avoids truncation on both desktop and mobile search results. Google typically cuts descriptions at around 920 pixels width, which translates to roughly 155–160 characters depending on letter width (W's and M's take more space than i's and l's). Mobile results are tighter and often truncate around 120 characters, but Google pulls from your description dynamically based on the query, so writing a full 155-character description gives the algorithm more material to work with. The search engine doesn't always use your meta description anyway—it generates its own snippet about 70% of the time by pulling relevant sentences from your page content. Practical guidelines we follow at Ottawa SEO: - Front-load your primary keyword and value proposition in the first 120 characters - Write for humans first, treating it as ad copy that drives clicks - Include a clear benefit or call-to-action when space allows - Avoid cutting off mid-sentence at 155 characters; adjust phrasing to end cleanly - Test critical pages in Google's SERP preview tools or browser extensions Descriptions longer than 160 characters aren't penalized—Google just won't show the excess. Going to 300 characters can work for informational content where Google might pull different segments for different queries, but for commercial pages targeting specific keywords, tight 150–160 character descriptions perform better because you control the message. One counterintuitive finding: pages without meta descriptions sometimes get higher CTR because Google's auto-generated snippets include the exact search term in context, which bolds in the results and draws the eye. For transactional pages we always write custom descriptions, but for deep informational content in the 500+ domain portfolio, we often let Google choose, then monitor Search Console CTR data to decide whether a manual description improves performance.