Edit the fields and watch Facebook and Twitter/X cards render live. Toggle the image off to see how a broken/relative og:image looks.
Titles truncate at ~600px and descriptions at ~920px — by pixel width, not character count. Watch the bars turn amber then red as you approach the limits.
Fill in the essentials and copy a correctly-ordered, escaped meta block. Note how Twitter inherits from Open Graph — only twitter:card is emitted.
The one Twitter tag you must set. Without twitter:card, X defaults to the small square summary — even if you have a big image ready.
name=, not property= (the opposite of Open Graph). Mixing them up is a silent failure.
Paste a <head> (or use the sample) and check it against the traps: relative URLs, missing twitter:card, charset placement, unescaped characters, and length.