Do This Before You Do Anything Else
Before you report the content to a platform, before you call an attorney, before you confront anyone — take screenshots. I say this to nearly everyone who contacts me about a defamation matter, and I say it based on years of watching cases where the single limiting factor wasn't the strength of the claim, it was that the evidence was gone by the time anyone thought to capture it.
Do It Right the First Time
A cropped screenshot of just the offending sentence isn't enough. Capture the full page, including the visible URL in your browser's address bar, the date and time (your device clock, plus the platform's own timestamp on the post if one is shown), the poster's username or profile, and any surrounding context — comments, replies, or engagement — that shows how the content was being seen and shared. If your device supports a full-page screenshot rather than just the visible window, use it. On most browsers, "print to PDF" also captures a full, scrollable page well.
Beyond the Screenshot
Where possible, also save the page's source (most browsers let you save a full webpage, not just an image), note the exact date and time you captured it, and if you're able to, capture the poster's profile page separately, since profile information can change or disappear independently of the specific post.
Avoid These Mistakes
Don't engage with or comment on the post before you've preserved it — that can prompt the poster to delete or edit it. Don't rely on a single screenshot alone; capture the profile, the post, and any related comments separately. And don't wait, even a day, if you can help it — content on social media can disappear faster than people expect.