Introducing ByteDance Seedance V1.5 Pro Video Extend Fast on WaveSpeedAI

Extend Your Vision: ByteDance Seedance 1.5 Pro Video Extend Fast Arrives on WaveSpeedAI

The creative video landscape just got a powerful new tool. ByteDance’s Seedance 1.5 Pro Video Extend Fast is now available on WaveSpeedAI, bringing enterprise-grade video extension capabilities to creators, marketers, and production teams who need to turn short clips into longer, polished content without starting from scratch.

Built on ByteDance’s acclaimed Dual-Branch Diffusion Transformer architecture, this model doesn’t just add frames to your video—it intelligently continues your story while preserving everything that makes your original footage work.

What is Seedance 1.5 Pro Video Extend Fast?

Seedance 1.5 Pro Video Extend Fast is a specialized video-to-video AI model designed to extend existing clips by 4 to 12 seconds while maintaining motion continuity, subject consistency, and scene coherence. Unlike simple frame interpolation tools, this model understands the context of your video and generates new content that flows naturally from where your original footage ends.

The “Fast” designation indicates optimized inference speed, making this variant ideal for iterative workflows where you need quick turnarounds during the creative process. It’s part of ByteDance’s Seedance 1.5 Pro family, which has earned the top position on the Artificial Analysis Arena Leaderboard for both text-to-video and image-to-video generation—outperforming OpenAI Sora, Google Veo 3, Kling 2.x, and Runway Gen4.

Key Features

• Natural Motion Continuation: The model analyzes your input video’s motion rhythm and visual style, then extends movement in a way that feels like an uninterrupted continuation rather than a jarring addition.

• Scene Coherence Preservation: Lighting, composition, color grading, and identity cues remain stable across the extension. Your subjects stay recognizable; your aesthetic stays intact.

• Prompt-Guided Direction: Describe what should happen next using natural language. Want a slow zoom out? A character turning toward camera? A subtle smile? Simply tell the model, and it steers the extension accordingly.

• Flexible Resolution Output: Choose between 720p for fast preview iterations or 1080p for final deliverables. Built-in upscaling handles the quality lift automatically.

• Optional Audio Generation: Enable synchronized audio generation when your extended footage needs sound, or disable it for silent clips—with transparent pricing for each option.

• Seed Reproducibility: Lock in a specific seed value to get consistent results across multiple generations. Perfect for A/B testing prompts or matching shots across a project.

• Fixed Camera Mode: When your scene calls for a static shot, enable camera lock to prevent unwanted drift or movement in the extension.

Real-World Use Cases

Advertising and Commercial Production

That hero shot from your product video is perfect—but it needs to be three seconds longer for the 15-second cut. Instead of reshooting or resorting to awkward slow-motion, extend the clip with natural motion that maintains the energy of the original take.

Social Media Content Multiplication

Turn a single 5-second clip into multiple length variants for different platforms. Create a 9-second version for Instagram Reels, a 12-second cut for TikTok, and a 15-second edit for YouTube Shorts—all from the same source material.

Short-Form Drama and Storytelling

Extend key emotional beats without disrupting narrative flow. Hold on that reaction shot, let the tension build in a confrontation scene, or give your establishing shots room to breathe.

Marketing Asset Adaptation

When your brand guidelines require specific durations for different placements, video extension lets you adapt existing approved content rather than producing new footage for every format.

Trailer and Teaser Creation

Stretch compelling moments to hit timing marks for music or voiceover. Extend transitions between scenes to create smoother cuts in your edit.

Getting Started on WaveSpeedAI

Accessing Seedance 1.5 Pro Video Extend Fast through WaveSpeedAI takes just minutes:

1. Navigate to the model: Visit the model page to access the interface.

2. Upload your input video: Provide a clean source clip with clear subjects and stable exposure for best results.

3. Write your extension prompt: Be specific but concise. State what should happen and what should stay the same. For example: “Continue the scene with a slow zoom out revealing more of the cityscape, maintain the same lighting and color grade, keep motion subtle and cinematic.”

4. Set your parameters: Choose duration (4–12 seconds), resolution (720p or 1080p), whether to generate audio, and whether to fix the camera position.

5. Generate and iterate: Start with 5-second extensions at 720p to validate your approach, then scale up to 1080p for your final output.

Pricing That Makes Sense

WaveSpeedAI offers straightforward, transparent pricing based on duration and resolution:

With Audio Generation:

• 720p: $0.04 per second ($0.20 for 5s, $0.40 for 10s)
• 1080p: $0.06 per second ($0.30 for 5s, $0.60 for 10s)

Without Audio:

• 720p: $0.02 per second ($0.10 for 5s, $0.20 for 10s)
• 1080p: $0.03 per second ($0.15 for 5s, $0.30 for 10s)

No subscriptions, no hidden fees—just pay for what you generate.

Pro Tips for Best Results

• Quality in, quality out: Use source videos with minimal compression artifacts, clear subjects, and stable exposure.
• Be explicit about consistency: If you want the character’s outfit unchanged, say so. If lighting must match, specify it.
• Iterate at low resolution first: 720p previews let you refine your prompt before committing to 1080p generation.
• Use fixed seeds for matching shots: When extending multiple clips from the same scene, a consistent seed helps maintain visual harmony.
• Add motion constraints when needed: Phrases like “keep face unchanged” or “maintain camera position” help prevent unwanted drift.

Why Choose WaveSpeedAI?

Running Seedance 1.5 Pro Video Extend Fast through WaveSpeedAI means you get:

• Fast inference: Optimized infrastructure delivers results quickly, letting you iterate without waiting.
• No cold starts: Your requests process immediately—no spinning up instances or queueing behind warm-up cycles.
• Production-ready API: Integrate video extension directly into your workflows with a clean REST API.
• Affordable pricing: Enterprise-grade AI at rates that work for individual creators and production teams alike.

Transform Your Video Workflow Today

Seedance 1.5 Pro Video Extend Fast represents a fundamental shift in how creators approach video content. Instead of planning shoots around exact duration requirements or padding edits with awkward holds, you can now intelligently extend your best footage while preserving everything that made it work.

Whether you’re a solo content creator stretching clips for multiple platforms, a marketing team adapting assets across formats, or a production house looking to maximize the value of every take, this model delivers the flexibility and quality modern video workflows demand.

Ready to extend your creative possibilities? Try Seedance 1.5 Pro Video Extend Fast on WaveSpeedAI now and experience the future of AI-powered video production.