Facebook Ad Preview — Live Feed Mockup & Character Limits

Facebook ad character limits that actually matter

Facebook does not publish a single hard "ad limit" — what trips up advertisers is truncation. On the Facebook Feed, your primary text is cut off at roughly 125 characters, after which the platform appends an unclickable "… See More". Everything past that point is hidden unless the viewer taps to expand, and most never do. The simulator above shows that cutoff live, so you can guarantee your hook and value proposition land above the fold.

Headline and description rules

The headline is the bold line beneath your creative. Facebook recommends keeping it short, and on mobile a headline longer than about 40 characters gets squeezed or wraps awkwardly; under 27 characters is the safest zone for full visibility across placements. The link description caps around 30 characters and is frequently dropped entirely when the headline is long or the placement is narrow — never put critical information there.

Mobile versus desktop

The overwhelming majority of Facebook ad impressions are mobile, and mobile is far less forgiving: less horizontal room, earlier truncation, and a higher chance the description disappears. Toggle the preview between Mobile and Desktop to confirm your ad reads cleanly on the placement that matters most — the small screen.

Why preview before you publish

Rewriting an ad after it has entered review wastes time and can reset its learning phase. Checking truncation in advance means your strongest copy is never buried behind "See More," your headline never clips, and your call to action stays visible. Because PostTruncate runs entirely in your browser, nothing you paste is uploaded or stored — type your draft, watch the cutoff in real time, and copy the final version straight into Ads Manager.