The AI video generator that comes with sound
In short
TL;DR: most AI video models output silent clips, so you still owe an audio pass. Fattly runs Veo 3.1, which generates video with sound built in — dialogue, ambience and effects, in your language.
Silent AI video is only half a video
Most AI video generators hand you a beautiful clip with no sound. It looks great on mute, but a muted clip is not finished — you still have to record a voiceover, find music, layer in effects and pray the timing lines up. In a feed where sound-on drives watch time, that second stage is where most AI video quietly falls apart. The clip exists; the video does not.
What changes when the sound is generated with the picture
When a model generates the audio together with the video, the two are locked from the start: a character's line matches their mouth, footsteps match the steps, the room tone fits the room. There is no separate dubbing pass and no drift to fix. You describe the scene, and what comes back already sounds like a real shot — dialogue, ambience and effects included. That is the difference between a clip you post and a clip you keep editing.
What to expect from AI video with sound
Before you judge a video model, check whether its output actually arrives finished:
- Dialogue and voices generated in sync with the character
- Ambient sound and effects that fit the scene, not a stock loop
- Output in your language, including Polish, not only English
- Text-to-video and image-to-video from a single photo
- Vertical or wide framing for the feed or for YouTube
- No separate audio tool, timeline or dubbing step
How Fattly generates video with sound
Fattly runs the full Veo 3.1 family — Google's video model that generates picture and audio together. You write a prompt, or upload a photo to bring to life, and get back a clip that already speaks: dialogue, sound and effects synced to the frame, and it works in Polish, not only English. You keep control of the shot while the model handles the hard part of making it sound real.
Veo sits alongside 50+ AI models for image, video and audio under one roof, so the rest of your production lives in the same place. It is pay-per-credit, credits never expire and there is no mandatory subscription — you only pay for the clips you actually render.
| What to look for | Silent AI video | Fattly (Veo 3.1) |
|---|---|---|
| Sound | None — you add it later | Generated with the picture |
| Dialogue | Dubbed separately | Voiced in sync with the character |
| Language | Usually English-only | Works in Polish, German, Spanish |
| Input | Text only | Text or a single photo |
| Editing | Separate audio timeline | Comes back finished |
| Pricing | Per-seat subscription | Pay per credit, credits never expire |
What people make with it
Marketers who need a talking product scene without a shoot; creators building short cinematic clips with real dialogue; founders animating a single product photo into a moving shot with sound; and teams localising the same scene across markets by prompting it in another language. Anywhere you would have filmed a short scene or stitched audio onto a silent clip, a video model with built-in sound does both at once.
Try a scene with sound
The honest test is a scene you would actually use. Write a short prompt with a line of dialogue, or upload a product photo to animate, and generate one clip. With Fattly you can do that on free credits — hit play with the sound on and judge whether it arrives finished before you build anything around it.
Frequently asked questions
Does the AI really generate the sound, or do I add it afterwards?
The sound is generated together with the video, not added afterwards. Veo 3.1 produces dialogue, ambience and effects synced to the picture in one pass, so the clip comes back finished instead of silent. You can hear it for yourself on a short clip with free credits before committing.
Can the video speak Polish, not just English?
Yes. The Veo 3.1 family on Fattly works in Polish, German and Spanish, not only English, so the dialogue in your clip can be in your own language with matching delivery. That lets you make the same scene for several markets by prompting it in each language.
Can I turn a photo into video, or only text?
Both. You can generate video from a text prompt or from a single photo you upload, which is ideal for bringing a product shot or a portrait to life. The audio is generated with the motion either way, so the result already has sound.
How much does it cost to try?
You start with 10 free credits and no card, enough to render a short clip and hear the sound. After that it is pay-per-credit — credits never expire and there is no mandatory subscription, so you only pay for the clips you generate.
Ready to try?
Try the AI video generator