Facebook feed ad text 50-150 characters, headline 27: what Sume burns

Meta's Facebook feed video page lists 50 to 150 characters for primary text and 27 characters for the headline, and the Instagram feed page caps primary text at 125 characters with a maximum of 30 hashtags. Those fields live in Ads Manager, not in the video file. Sume's video captions API burns text into the picture, so it cannot fill or check either field.

The two field lists

Three different places for words

Words about an ad end up in three places. The primary text and headline are metadata sent with the ad. Auto-generated captions are produced by the platform. Burned-in captions are pixels in the MP4. Only the third belongs to the file you render.

Sume's caption job returns a new video with text drawn into the frames, either from speech-to-text or from authored cues you send. It costs $0.20 per job for videos up to 60 seconds, and the clip must be a public HTTPS URL. A burned caption does not change the primary text limit, and it will not appear in any Ads Manager field.

A short budget for copy

Keep three lines in a note per ad: a primary text for Facebook of 50 to 150 characters, a version for Instagram of 125 characters or fewer, and a headline of 27 characters. Write the Instagram version first. At 50 to 125 characters it fits both pages, so one line can serve both placements.

What Sume does not do

Sume does not count characters for Meta fields, write ad copy into Ads Manager, or add hashtags. It also does not pass captions as a separate track: the burned text is permanent, so a mistake means another $0.20 job. Review the cues before you submit them.

A practical order of work: lock the video first, then write the three text lines against the page limits, then decide whether the picture needs burned captions at all. Both Meta pages call captions optional but recommended, so a short burned line is a choice, not a requirement. The line should repeat what the primary text says, not extend it, so the ad still reads if either one is cropped by the placement.