Fill the form on the left: page title, meta description (target ~150–160 chars), canonical URL, optional OpenGraph / Twitter overrides, image URL and keywords. Fields left blank fall back to the page title / description, so you only need to set them when you want a different social-card copy. The HTML block on the right is syntax-highlighted and updates live — click Copy to grab it. The Google SERP preview above shows roughly how the title (≤60 chars) and description (≤160 chars) would be truncated in search results; lengths outside the recommended range are flagged.