Ad copy and captions that get read
Most people read only what shows before "See more". Put the whole promise there, test one thing at a time, and write captions for search, not for decoration.
125 characters
Meta cuts primary text at about 125 characters on mobile. The hook and the offer go before that.
27 / 40
Headlines: about 27 characters in Facebook feed, about 40 in Instagram feed before they are cut.
One at a time
Change one element per test (hook, body or call to action) or you will not know what won.
A 4-week testing rhythm
- Before week 1: confirm the angle works with a small test (see the static ads lesson).
- Week 1: 4 hooks against your current best body and call to action.
- Week 2: 3 bodies with the winning hook.
- Week 3: call to action variants.
- Week 4: your best combination against one brand new concept. Then repeat. Keep a swipe file of winners by placement.
Captions for TikTok and Instagram
- Open with the keyword: the product type and the problem, the same words as the on-screen text and the voice
- 3 to 5 precise hashtags at the end
- A clear reason to save or send in the last line
- #ad at the start when the post is paid, gifted or on commission
- Opening with "hey guys" or an emoji wall
- Primary text that only makes sense after "See more"
- A 12-combination test on a small budget
Questions
How many ad texts does CartViral write?
Several primary texts and headlines in different angles, so you can run the 4-week rhythm without writing anything yourself.
Are long captions better on Instagram?
Length alone is not a ranking signal. Write what the post needs, with the keyword first.
Sources
- Jupitron: Meta primary text accessed 2026-10-16
- Headline character limits by platform 2026 accessed 2026-10-16
- Creative Milkshake: creative testing framework accessed 2026-10-16
- SeoSherpa: TikTok as a search engine accessed 2026-10-16
Make it with Text and SEO
Primary texts and headlines for Meta and TikTok in several angles, plus captions with hashtags for your posts. 1 credit each, from your product's facts.