The explainer video is the hardest-working asset in B2B marketing: 60-90 seconds that must hook a stranger, explain a product, and drive a demo booking. And the voiceover carries roughly half that load — tone, clarity, and pacing decide whether viewers watch or bounce.
AI voiceover is now the default for explainers because they iterate constantly: positioning changes, features launch, pricing updates. Re-recording a voice actor for every tweak is unsustainable. ## Key Takeaways
- The winning explainer structure: problem → agitate → solution → how it works → proof → CTA, in 60-90 seconds.
- Write 130-150 words for a 60-second explainer; every word must earn its place — cut ruthlessly.
- Conversational, confident voices outperform both corporate-stiff and zany reads for B2B explainers.
- Animate to the voiceover: lock narration first, then time visuals to it.
- Version your scripts — explainers update quarterly, and AI narration makes each update a 10-minute job.
The 90-Second Script Formula
This structure has sold billions in software. Timings for a 90-second video (~200 words):
0-10s: The problem. Name the pain your buyer feels daily: "Your team wastes 6 hours a week on manual reporting." Specific numbers beat vague complaints.
10-20s: Agitate. What does the problem cost? "That is 300 hours a year — almost two full work months."
20-30s: The solution. Introduce the product as the answer: "Acme automates your reporting in one click."
30-60s: How it works. Three steps, maximum. "Connect your data. Pick a template. Share the dashboard." Show, do not tell — the visuals demonstrate while the voice guides.
60-75s: Proof. One customer result, one stat, one logo wall mention: "Teams at 2,000+ companies save 6 hours weekly."
75-90s: Call to action. One action, low friction: "Start your free trial — no credit card required."
Write the script, then cut 20%, then 10% more. Explainer scripts start too long because founders want every feature mentioned — the voiceover is not the place for the feature list.
Choosing the Right Explainer Voice
Match voice energy to your buyer and brand:
| Brand / Audience | Voice Style | Pace | Avoid |
|---|---|---|---|
| B2B SaaS (default) | Confident, conversational | 140-150 wpm | Corporate-stiff reads |
| Developer tools | Smart, direct, slightly dry | 145-155 wpm | Hype and exclamation |
| Fintech | Trustworthy, precise | 130-140 wpm | Over-casual slang |
| Consumer apps | Friendly, upbeat | 150-160 wpm | Monotone |
| Healthcare | Calm, empathetic, clear | 125-135 wpm | Rushing complex terms |
| Enterprise | Authoritative, polished | 135-145 wpm | Trendy casualness |
The most common mistake is the "movie trailer" voice — dramatic reads feel dishonest in B2B. The second most common is monotone: if your narrator sounds bored, viewers assume the product is boring. Aim for the energy of a smart colleague explaining something exciting over coffee.
Generate the full script in your top 2-3 voices against a rough animatic. The right voice makes visuals feel 20% better; the wrong one fights them.
Production Workflow: Voice First
1. Lock the script. Get sign-off on the words before generating. Script changes after animation starts are the #1 budget killer.
2. Generate the master narration. Use SynVoice with your brand voice, generating in sections so revisions touch only what changed.
3. Build the animatic. Time rough visuals to the narration waveform. This is where pacing problems surface — if a 15-second section needs 25 seconds of visuals, rewrite the script, not the animation.
4. Animate to the audio. Professional studios animate to a locked voice track. Every visual transition should land on a vocal beat.
5. Mix and master. Voice front and center, music bed 12-15dB down. Check the mix on laptop speakers — that is where your buyers watch.
6. Version and localize. Save the script as v1.0; when positioning changes, update the script, regenerate changed sections, and re-export. For new markets, translate and generate localized narration — animation usually needs no changes.
Measuring Explainer Performance
A voiceover is not done when it sounds good — it is done when it converts:
- Watch-through rate: below 50% usually means the hook is weak — rewrite the problem statement, not the voice.
- CTA click-through: test two CTA wordings with identical visuals. "Start free trial" versus "See it in action" can differ by 30%+.
- A/B test the voice: run the same video with two voice styles to a split audience. Voice is a conversion variable — test it like a headline.
- Heatmap drop-offs: if viewers leave during "how it works," the section is too long or too detailed. Cut it in the script and regenerate.
Because AI narration makes variants nearly free, build testing into the process: every explainer ships with at least two voice or script variants. The compounding gains from quarterly creative tests dwarf any single "perfect" voiceover.
Frequently Asked Questions
How many words should an explainer video script be?
130-150 words for 60 seconds, 200-225 for 90 seconds, at 140-150 wpm. Write long, then cut twice — founders always want every feature mentioned. If it does not fit, cut words, never speed up the voice.
Should the voiceover or animation come first?
Voiceover first, always. Lock narration, then animate visuals to the audio. Animating first forces unnatural timings that sound rushed and look amateur. Studios treat the voice track as the foundation.
What voice style works best for SaaS explainers?
Confident and conversational — like a smart colleague explaining something exciting. Avoid both corporate-stiff reads (boring) and movie-trailer drama (dishonest). Match energy to audience: developers want direct, fintech wants trustworthy, consumer apps want upbeat.
How do I update an explainer video when our product changes?
Update the script, regenerate only changed sections with the same AI voice, and re-export. Keep scripts versioned so any video is reproducible. What required re-booking a voice actor is now a 10-minute task.
Can I make multilingual versions of my explainer?
Yes — translate the script, have a native speaker review it, and generate localized narration with a native-quality voice. The animation usually needs no changes, making multilingual explainers one of the highest-ROI uses of AI voiceover.
Related Guides
- How to Write Scripts for AI Voiceover
- AI Voiceover for Online Courses
- CapCut Text to Speech Alternative
Ready to put this into practice? Try SynVoice free — generate studio-quality voiceovers in minutes, with a generous free tier and no credit card required.