Because runtime comes from your script, not from the length you type in. Each paragraph becomes a scene, and each scene lasts about as long as its spoken lines. A 2 minute video needs enough scenes and enough narration to fill 2 minutes. Plan both before you generate, check them in Storyboard, then add scenes in the editor if you're short.

You asked for a 2 minute story. The video finished at 57 seconds. Another script you thought was about 3 minutes came back at 141 seconds, and a third at 175. Nothing broke. The length of an AI story video is the sum of its scenes, and the scenes come from what you wrote.

This guide shows how runtime is really built in the Atlabs Animated Video workflow, how to write a script that lands on your target length, and the checks that catch a short video before you spend credits on the full render.

Why scene count and per scene length set the final runtime

The runtime of your video is simple arithmetic: number of scenes × average length of a scene.

Scene count comes from your paragraphs. Each paragraph of your script becomes one scene. A 2 minute idea written as four long paragraphs gives you four scenes, no matter what length you asked for. Timestamps added at the input step also shape how many scenes Atlabs creates.

Scene length comes from what is spoken. In a narrated story, a scene lasts about as long as its narration and dialogue, plus any Scene End Pause you add in the scene's Settings tab, which is 0 seconds by default. Short lines make short scenes.

So a short video has one of two causes. Either there are too few scenes, or there are too few words in each one. The 57 second result above is what a 2 minute idea looks like when it is written in roughly half the words it needs.

A useful rule of thumb: most narrators speak at about 130 to 160 words a minute. A 2 minute video needs roughly 260 to 320 words of narration and dialogue. A 3 minute video needs roughly 390 to 480. Count your words before you paste the script in.

What you'll need

A script written to length, with a word count that matches your target runtime using the rule above. A plan of scenes, with each scene's intended duration. And your characters ready, either saved in your Atlabs library or as reference images, so you don't regenerate them while you fix the length.

How to get the length you asked for, step by step

Step 1: Structure the script into scenes with intended durations

Before opening Atlabs, plan your story as a list of scenes. Give each one an intended duration, then write the narration for it at about 2 to 3 words per second.

• Target 2 minutes, 12 scenes of about 10 seconds each. Each scene needs about 22 to 27 spoken words.

• Write one paragraph per scene. Each paragraph becomes one scene, so 12 planned scenes means 12 paragraphs.

• Add up the durations. If your scene plan doesn't add up to your target, the video won't either.

A scene with one short line, such as "She opened the door.", will last only a couple of seconds. If a moment needs to breathe, write more narration for it or plan a Scene End Pause.

Step 2: Paste the script in Script

Open the Animated Video workflow. In Script, paste your scene by scene script, or type a prompt and use the AI Script Writer, then set your language and click Continue. If you use the AI Script Writer, check its word count against your target before continuing, since a short draft makes a short video.

Step 3: Set up your cast in Cast

In Cast, choose the narrator's voice and accent, and review the characters, locations and objects pulled from your script. Upload your own character images if you have them, then click Continue.

Cast: set the narrator and characters once, so fixing the length later never means recasting.

Step 4: Count your scenes in Screenplay

In Screenplay, every scene shows its location, visual shot and dialogue. This is the first place to check length. Count the scenes and skim the dialogue in each. If you planned 12 scenes and see 7, or a scene has one short line, fix it here. Dialogue can only be edited in this step, before generation.

Screenplay: count scenes and check each one's dialogue before you click Finalise.

Step 5: Use Storyboard to check scene count before spending credits

Click Finalise and choose Storyboard. It generates the still image for every scene, without motion or lip sync for the whole video. Use it to confirm the scene count and the order of the story. A missing beat is much cheaper to spot as a still than as a finished render.

Step 6: Preview the opening with a Video Teaser

Choose Video Teaser to render a 20 to 25 second preview of the opening scenes with full motion. Time how far into your script those 20 to 25 seconds get you. If the teaser covers three planned 10 second scenes, your pacing matches the plan. If it races through five, your scenes are short and the full video will be too.

Step 7: Add scenes in the editor to reach the target length

If the video is still short, open it with Edit Video and add scenes.

• Add a scene. Use the + icon on any scene card to insert an empty scene beneath it, or choose Add new scene from the scene's three dot menu.

• Split a long scene. In the Split Scene tab, click the word where the cut should go and confirm. The scene becomes sub scenes, such as 1.1 and 1.2, that you can edit separately.

• Hold a moment. In the scene's Settings tab, set a Scene End Pause to add a hold at the end of the scene, useful for an ending card or a dramatic beat.

Timestamps update automatically when you reorder scenes, so you can check the new total as you go.

Step 8: Render the Full Video

When the scene count matches your plan and the teaser pacing looks right, choose Full Video. You can close the window while it generates and find it in My Stories.

Watch the Animated Video tutorial

Keep motion prompts under the length limit

When you change a scene's movement in the Motion tab, the prompt you write has a character limit set by the video model you pick. In Atlabs, Kling 3.0 takes up to 2,500 characters, Google Veo 3.1 and Hailuo 2.3 take up to 5,000, Seedance 2.0 takes up to 10,000, Runway Gen 4 Turbo takes up to 1,000 and Wan 2.6 takes up to 800.

A prompt over the limit won't run, so write for the smallest limit you plan to use. Keep each prompt about one scene: who is in it, what they do and one camera move. Don't paste your whole script into a motion prompt. The script belongs in the Script step, where it sets the scenes.

The model also sets each clip's possible length. Veo 3.1 clips run 4, 6 or 8 seconds, Kling 3.0 runs 3 to 15 seconds, and Hailuo 2.3 runs 6 or 10 seconds. A scene with 12 seconds of narration needs a model that can make a clip that long.

Tips for hitting your target length

Count words, not minutes. The number you type for length is a wish. The word count is what the video is made of.

Plan more short scenes, not fewer long ones. Twelve 10 second scenes are easier to time and fix than four 30 second ones.

Check length at every cheap stage. Count scenes in Screenplay, confirm them in Storyboard, time the Video Teaser, and only then render the Full Video.

Fix the script first, the edit second. Adding scenes in the editor works, but a script written to length saves the extra steps.

FAQ

Why is my AI video shorter than the length I asked for?

Runtime comes from the number of scenes and how long each one runs, and both come from your script. Each paragraph becomes a scene, and each scene lasts about as long as its spoken lines. A short script makes a short video.

How many words do I need for a 2 minute AI video?

As a rough guide, about 260 to 320 words of narration and dialogue, since most narrators speak about 130 to 160 words a minute. Split them into one paragraph per planned scene.

How do I make my AI video longer after it's made?

Open Edit Video and add scenes with the + icon or Add new scene, split long scenes with Split Scene, or add a Scene End Pause in a scene's Settings tab.

Can I check the length before spending credits on the full video?

Yes. Count scenes in Screenplay, generate a Storyboard to see every scene as a still, and render a Video Teaser to time the opening. Then render the Full Video.

Final verdict

An AI story video that comes out short is almost always a script that is short. Runtime is scenes times scene length, each paragraph becomes a scene, and each scene lasts about as long as its narration. Write to a word count, plan one paragraph per scene with an intended duration, count scenes in Screenplay, confirm them in Storyboard, time the opening with a Video Teaser, and add or split scenes in the editor if you still need more. Keep motion prompts under your model's limit and matched to one scene each. Do that and a 2 minute request comes back as a 2 minute video.