Updated
ByteDance
Seedance 1.5 Pro
ByteDance's audio-video model: 12-second clips with native sound and multilingual lip-sync.
What is Seedance 1.5 Pro?
Seedance 1.5 Pro is ByteDance's joint audio-video model, released around December 2025, before the Seedance 2.0 generation.
It generates picture and sound together in one pass and lip-syncs speech in several languages. On Flashloop it renders up to 12 seconds at 480p, 720p or 1080p in 16:9, 9:16 or 1:1.
ByteDance built it with two branches, one for video and one for audio, that talk to each other while the clip is generated. That is why a character's mouth tends to match the line you wrote, including in Mandarin, Japanese, Korean and Spanish, and in Chinese dialects such as Cantonese. For short spoken content, like a product line to camera or a character reacting in a scene, it gets you usable audio without a separate voice step.
It is not the newest Seedance. Seedance 2.0 adds 4K and stronger camera control, and 2.5 adds 30 second takes. Seedance 1.5 Pro still earns its place as a quick, cheaper option for voice-led clips, and most renders on Flashloop come back within a few minutes.
- Provider
- ByteDance
- Length
- 12 seconds
- Resolution
- 480p, 720p, 1080p
- Aspect ratios
- 16:9, 9:16, 1:1
- Audio
- Native audio
What you can do with Seedance 1.5 Pro
Audio and video in one render
dialogue, effects and ambience are generated with the picture
Multilingual lip-sync
English, Mandarin, Japanese, Korean and Spanish, plus several Chinese dialects
Quick turnaround
most renders on Flashloop finish in about 45 seconds to 3 minutes
Three resolutions
480p and 720p for drafts, 1080p for finals
Dual-branch design
separate video and audio branches generated in step with each other
Up to 12 seconds, enough for a short ad, an explainer beat or a spoken line
Prompts to try with Seedance 1.5 Pro
“A smiling barista in a bright cafe holds up a cup to the camera and says "Prueba nuestro nuevo latte de vainilla." Espresso machine hiss and soft acoustic guitar. 6 seconds, 9:16.”
Where Seedance 1.5 Pro fits best
The same ad in several languages
Keep the scene and swap the spoken line for each market, written directly in Spanish, Japanese or Mandarin.
Character reactions with dialogue
Short animated or stylized scenes where a character delivers one line with matching lip movement.
Quick social clips with voice
A 9:16 clip up to 12 seconds, with the voice and background sound already in place.
Concept tests before Seedance 2.0
Check whether a spoken idea works here first, then move the winner to Seedance 2.0 for higher fidelity.
How Seedance 1.5 Pro compares
| Model | Length | Top resolution | Aspect ratios | Native audio |
|---|---|---|---|---|
| Seedance 1.5 Pro | 12 seconds | 1080p | 16:9, 9:16, 1:1 | Yes |
| Veo 3.1 | 8 seconds | 1080p | 16:9 | Yes |
| Kling 3.0 | 15 seconds | Pro (1080p) | 16:9, 9:16, 1:1 | No |
| Kling 3.0 Turbo | 15 seconds | 1080p | 16:9, 9:16, 1:1 | No |
| Kling 4.0Coming soon | 30 seconds | To be confirmed | To be confirmed | Yes |
Good to know before you generate
- 480p previews are soft, so treat them as layout checks
- Clips stop at 12 seconds, shorter than Seedance 2.0 or Kling 3.0
- On Flashloop it offers three aspect ratios: 16:9, 9:16 and 1:1
- It is an older generation than Seedance 2.0 and 2.5
Start creating with Seedance 1.5 Pro
Create with Seedance 1.5 ProSelect Seedance 1.5 Pro
Open Flashloop and choose Seedance 1.5 Pro from the model selector in the video creator.
Enter your prompt
Describe what you want to see in your video.
Generate and download
Hit generate and your video will be ready in seconds. Download or share directly.
Questions about Seedance 1.5 Pro
Does Seedance 1.5 Pro generate audio?
Yes. It generates video and sound together, including dialogue, effects and ambience, instead of adding audio afterwards.
How long can Seedance 1.5 Pro videos be?
Up to 12 seconds, which fits short promos, social clips and quick concept videos.
What resolutions does Seedance 1.5 Pro offer?
480p, 720p and 1080p. The lower two are for fast testing and 1080p is for final exports.
How fast is Seedance 1.5 Pro?
Most renders on Flashloop take about 45 seconds to 3 minutes, depending on resolution, prompt complexity and the current queue.
Which languages does Seedance 1.5 Pro lip-sync?
Sources for the model list English, Mandarin, Japanese, Korean and Spanish, plus Chinese dialects such as Cantonese and Sichuanese. Write the line in the language you want spoken.
What is Seedance 1.5 Pro best for?
Short, voice-led videos: multilingual social posts, ad variations, explainers and quick concept work.
Who makes Seedance 1.5 Pro?
ByteDance's Seedance team, which described it in a technical paper as a native audio-visual joint generation model. Flashloop offers it as one of several video models on the platform.
Is Seedance 1.5 Pro better than Seedance 2.0?
No, 2.0 is the newer and stronger model, with 4K output and better camera control. Seedance 1.5 Pro is a quicker, lighter choice for short voice-led clips.
More video models on Flashloop
Veo 3.1Google DeepMind's Veo 3.1: 8-second videos with dialogue, sound effects and ambience generated in one pass.
Kling 3.0Kuaishou's Kling 3.0: multi-shot video up to 15 seconds, with consistent characters across cuts.
- Kling 3.0 Turbo
Kuaishou's faster, cheaper Kling 3.0: text and image to video at 720p or 1080p, up to 15 seconds.
Kling 4.0Kuaishou's Kling 4.0, announced September 28, 2026: native 30-second clips, up to 10 keyframes, full release in October.