A great Video ad starts with a great script. It’s everything your AI avatar says on camera, and it’s made of two parts: the Hook, which grabs attention, and the Body, which delivers your message. Get both right, and viewers will stop scrolling, listen, and know exactly what to do next.
Here’s how to write a script that sounds natural, fits the limits, and doesn’t use more credits than it needs to.
What the Hook and Body are
Hook script: The opening line of your video, designed to capture the viewer's attention. On Instagram Reels or TikTok, people decide in the first 2–3 seconds whether to keep watching or scroll past, so the Hook has one job: make them stay.
Body script: The main part of the video, where the avatar delivers your message: what you offer, why it's worth it, and what the viewer should do next.
Here's how it looks in a Street interview video:
Hook: What's the secret to hitting your hardest training sessions?
Body: Honestly? This drink. I have it 30 minutes before every workout, and I don't crash halfway through anymore. Tap the link and try it.
You don't have to write the script from scratch. Zeely suggests a Hook and a Body based on your product, and you can edit them or click Generate script to get a new version.
When to use Full video ad, Hook, or Body
In most cases, you'll start with a Full video ad. The Hook and Body options are useful later, when you already have a video and want to change only one part of it.
Full video ad: Use it when you're creating a new ad. Zeely generates both the Hook and the Body.
Hook: Use it when people scroll away in the first seconds, or when you want to test several openings for the same message. Zeely generates only the opening, so you don't recreate the Body.
Body: Use it when the opening works, but you want to change the main message, for example, a new offer, price, or call to action. Zeely generates only the main section while keeping the existing Hook.
To create only a Hook or a Body for a video you already have, open your Video ad and click Reuse context. The editor opens with the same settings and scripts, split into the Full video ad, Hook, and Body tabs. Switch to the tab you need, edit the script, and click Create video.
Example: Let's say you sell a pre-workout drink.
You create a Full video ad with the Hook "What's the secret to hitting your hardest training sessions?"
You want to know if another opening works better, so you open the video, click Reuse context, and switch to Hook. You write "I used to quit every workout halfway. Not anymore." and create a new Hook. The Body stays the same.
Next month you launch a 20% discount. The Hook still works, so you switch to Body and add the new offer to the script.
Good to know: A Hook or Body is shorter than a Full video ad, so it uses fewer credits. If you only need to change one part, there's no need to pay for the whole video again.
How much text to add
The character counter under each script field shows how much text you can enter, for example, 59 / 160. The limit depends on the selected AI model and video part.
AI model | Character limit per script (Full video ad) | Full video ad duration | Hook or Body duration |
Kling O3 Pro | 160 | 6–20 seconds | Up to 10 seconds |
Seedance 2.0 | 240 | 8–30 seconds | 4–15 seconds |
An avatar speaks about 2–3 words per second. As a guide:
Hook: 1 short sentence, up to 10–12 words (about 4–5 seconds).
Body: 2–3 short sentences, 20–30 words (about 10–15 seconds).
Short ads usually work best on social media. If you have more to say, it's better to create a few videos with one message each than one long video.
Good to know: Supported limits and durations may change over time. Always check the character counter and the model card before generating a video.
Examples of weak and strong scripts
A strong script sounds like a real person talking: short sentences, one idea, and a clear next step.
Hook examples
Avoid: Hello everyone, welcome to our store!
Try instead: Your coffee is cold by 10 am? Same.Avoid: Our innovative, high-quality, best-in-class skincare.
Try instead: I stopped wearing foundation after two weeks of this.Avoid: Check out our new collection on our website!
Try instead: Three outfits, one jacket. Watch this.
The "Try instead" versions ask a question, name a problem, or promise something the viewer wants to see. The "Avoid" versions sound like a typical ad, so viewers scroll past them.
Body examples
Avoid: Our mug is made of premium stainless steel and features double-wall vacuum insulation technology, which has been tested to keep drinks hot.
Try instead: This mug keeps my coffee hot for six hours. I fill it at seven and sip it till lunch. Tap the link to get yours.
The second version has one benefit, a real-life detail, and a call to action.
Best practice:
Write the way you speak: Read the script out loud before generating. If it sounds unnatural to you, it will sound unnatural from the avatar too.
Keep one message per video: Save other benefits for a new Body.
End with a call to action: For example, "Tap the link," "Shop now," or "Try it free."
Spell out numbers and symbols: Write "twenty percent off" instead of "20%," and "glow skin dot com" instead of a full link.
Avoid emojis and hashtags in the script: The avatar may read them in unexpected ways. If you want them on screen, add them to the hook headline instead.
For more tips on pronunciation, check out How to improve avatar movement and lip sync.
How video length affects the credit cost
Zeely calculates the video duration based on your script. A longer script results in a longer video and a higher cost, and a shorter script results in a lower one.
The credit cost depends on three things:
AI model: Each model has its own rate per second.
Resolution: Higher resolution may cost more. For example, Seedance 2.0 in 1080p costs more than in 720p.
Video duration: It's calculated for the part you're generating. A Hook is based on the Hook script, a Body on the Body script, and a Full video ad on both scripts combined.
AI model and resolution | Credits per second | 8-second video | 15-second video |
Kling O3 Pro, 1080p | 45 | 360 | 675 |
Seedance 2.0, 720p | 50 | 400 | 750 |
Seedance 2.0, 1080p | 100 | 800 | 1,500 |
The summary at the bottom of the screen shows the selected video part, AI model, resolution, and calculated duration. The Create video button shows the final credit cost before generation begins.
Important: Editing the script can change the calculated duration, and with it the total cost. After any change, wait for the updated amount on the Create video button before generating.
To learn more about AI models and settings, check out How to create Video ad.
What to do if your script is too long
If a script goes over the limit, Zeely won't let you generate the video, so no credits are used. You may see one of these:
The counter turns red and a message appears under the field, for example: Your body script is 15 characters too long. Shorten it to continue.
The script doesn't fit the model: Your script is too long for Seedance 2.0. Shorten it or choose another model.
A dash appears instead of the credit amount, and the Create video button becomes unavailable. This means the script exceeds the duration the selected model supports.
Here's what you can do:
Shorten the script: Remove greetings, repeated ideas, and extra adjectives. The message under the field shows how many characters you need to cut.
Shorten the middle, not the ending: Keep your call to action at the end, so viewers know what to do next.
Move text between the Hook and the Body: Each script has its own limit. If the Hook is too long, move part of it to the Body.
Choose another AI model: Seedance 2.0 supports longer scripts and videos (up to 30 seconds for a Full video ad) than Kling O3 Pro (up to 20 seconds).
Split it into several videos: Keep the same Hook and create a few Bodies, each with one message. This also helps you see which message works best.
If you need a hand or have any questions, feel free to reach out at [email protected] or open a chat. We're always ready to help.