What is a voice over generator, and how is it different from plain text to speech?
A voice over generator is a text-to-speech tool used for one specific job: producing narration that sits under a video, so every line has to land on the right shot. The voice is the same technology as text to speech, but the workflow is different. You write to a time budget, you render in scenes instead of one long file, and you choose a voice that matches the footage, not just one that sounds pleasant.
With Speechma Pro’s voice over generator you can do all of that in the browser: write a scene, pick a voice, listen, tweak the speed, and download an MP3 per scene. Then line those clips up on your editing timeline like you would with a human voice actor’s takes.
How do I make a voice over for my video?
- Time your footage firstNote how long each scene runs. A 45-second product clip with four shots needs four short lines, not one paragraph.
- Write to the clockBudget about 2.3–2.6 spoken words per second at a normal pace. A 10-second shot fits roughly 23–26 words.
- Pick a voice that fits the pictureFilter by language and country, preview a few voices, and favorite the two or three that suit your brand.
- Generate one scene at a timePaste each scene’s line and generate. Rendering per scene makes re-timing and fixes painless.
- Fine-tune pace and pitchIf a line runs long, nudge the speed up slightly or trim a few words rather than rushing the whole script.
- Download and syncDownload each MP3 (or everything as a ZIP) and drag the clips onto your timeline under the matching shots.
How many words fit in a 15, 30 or 60-second voice over?
These are practical ranges for clear English narration at default speed. Slower, calmer voices sit at the low end; upbeat ad reads sit at the high end.
| Video length | Typical word count | Approx. characters | Good for |
|---|---|---|---|
| 15 seconds | 32–40 words | 180–230 | Instagram Reels hook, pre-roll ad |
| 30 seconds | 65–80 words | 370–460 | TikTok explainer, local TV-style spot |
| 60 seconds | 130–160 words | 750–920 | YouTube Shorts, product demo |
| 2 minutes | 260–320 words | 1,500–1,850 | Real estate walkthrough, onboarding clip |
| 5 minutes | 650–800 words | 3,700–4,600 | Tutorial or training video (generate in parts) |
Each conversion takes up to 10,000 characters, which covers about two minutes of narration.
Which voice should I use for my video?
Match the voice to what the viewer is looking at. A mismatch, like a booming trailer voice over a gentle cooking clip, is the fastest way to make a video feel automated. Some reliable pairings:
- Product demos and SaaS walkthroughs: a friendly, mid-pitch American voice at normal speed. Try our product demo voiceover tips.
- Real estate tours: warm and unhurried, slightly slower than default so viewers can take in each room. See real estate video voiceover.
- Faceless YouTube channels: a consistent narrator you reuse in every upload so the channel has a recognizable “host.”
- Ads and promos: energetic, a touch faster, with short punchy sentences.
- Documentary or history content: a deeper, measured narrator voice with longer pauses.
Speechma Pro also has character-style AI voices (narrator, trailer, documentary, news and storyteller styles) for up to 10,000 characters per conversion conversion, which work well for intros and dramatic openers.
How do I make an AI voice over sound less robotic?
Most “robotic” voice overs come from the script, not the voice. Video narration should be written for the ear:
- Use punctuation as direction. A comma gives a short breath, a semicolon a medium pause, and an exclamation mark a longer, more emphatic stop. Add a comma before a reveal: “And the best part, it is included in Speechma Pro.”
- Spell out what should be spoken. Write “three bedrooms, two and a half baths” instead of “3BR/2.5BA,” and “fifty percent off” instead of “50% off.”
- Keep sentences under about 20 words. Long sentences make any voice sound like it is reading.
- Leave room for the picture. Silence over a strong visual is fine. You do not need to narrate every second.
Mini example for a 15-second Shopify product clip: “Meet the trail bottle. Keeps water cold for a full day; fits every cup holder. Grab yours today, and get shipping!” That is 21 words, leaving space for a logo card at the end.
For a deeper walkthrough, read how to make an AI voiceover sound human.
Why use Speechma Pro as your voice over generator?
No card
Open the page and start generating. There is nothing to sign up for.
Commercial use included
Use the narration in monetized YouTube videos, client work, ads and courses.
75+ languages and locales
US, UK, Australian, Canadian, Irish and Indian English plus dozens of other languages for localized versions.
Pitch, speed and volume
Adjust delivery per scene so each line fits its shot.
MP3 and ZIP export
Download single clips or every scene at once as a ZIP.
Private history
Your past generations are kept privately in your browser, not on our servers.
Frequently asked questions
Is this voice over generator included in Speechma Pro?
Can I use the voice over in monetized YouTube videos or ads?
How long can my voice over be?
How do I add the voice over to my video?
Can I make the voice over in another language?
Can I use my own voice for the voice over?
Can developers generate voice overs automatically?
Make better voiceovers, faster
- New voices and features the day they launch
- Script templates and tricks that make AI voices sound human
- Creator stories, community picks and early access