Picking the Best AI Video Model for Book Promo Videos and Trailers

I’m experimenting with AI generated promo videos and trailers for Doors to the Stars, and have been more than a bit overwhelmed by all the options out there.

So I dug into several major players in detail to understand what these AI video models actually do—not the marketing hype, but the real capabilities. The models listed below are all available under Freepix’s umbrella subscription, so individual pricing isn’t so much of a constraint, which makes things easier since this becomes a pure question of matching tool to task.

Bottom line upfront: Readers don’t care which AI model you use. They care whether the trailer made them want to buy the book. Keep that metric in mind when choosing between “technically impressive” and “actually effective.”

Google Veo 3 and 3.1 do something no other model manages as well: they generate native audio with actual character dialogue. Not placeholder sound effects you paste in later—synchronized conversations, ambient soundscapes, the works. If your trailer needs voiceover narration or characters speaking lines from your manuscript, Veo 3 is the only option that handles it natively. The prompt adherence is exceptional, meaning when you specify “low-angle shot, golden hour lighting, character looking uncertain,” it actually delivers on all three elements instead of ignoring half your instructions. Physics simulation holds up under scrutiny. The 3.1 Fast variant sacrifices some quality for speed when you’re testing concepts.

OpenAI Sora 2 understands physics in ways that expose how broken other models are. A basketball that misses the hoop bounces realistically off the backboard. Earlier models would just teleport the ball into the net because the prompt said “make the shot.” For authors writing action sequences—zero-gravity combat, water dynamics, complex object interactions—Sora 2 grasps how physical reality actually works. It maintains world state across shots, remembering what happened in the previous clip. Handles both photorealistic and anime aesthetics competently. Sora 2 Pro delivers the highest-quality version when you need maximum fidelity.

The Kling series from Kuaishou dominates dynamic motion. Kling 2.5 specifically excels at big, sweeping camera movements—tracking shots, dramatic reveals, intense action choreography. For space opera sequences (ship flyovers, combat, chase scenes through asteroid fields), Kling produces film-grade results. The motion physics are smooth and stable where other models stutter or warp. Kling 2.1 Master offers superior prompt adherence and particularly strong image-to-video conversion, letting you animate existing cover art or concept pieces. The standard 2.1 and 2.0 tiers trade some quality for efficiency, with 2.0 maintaining character integrity well during high-action sequences.

Runway Gen-4 solves character consistency—the problem that’s plagued AI video since the beginning. Upload a single reference image of your protagonist’s face, and Gen-4 maintains that appearance across multiple shots with different lighting, angles, and camera distances. This extends to objects and locations: a specific spaceship design stays visually consistent, a planet’s surface remains coherent. For narrative trailers that follow a character through several scenes, where continuity actually matters, Gen-4 is purpose-built. It’s designed specifically for multi-shot storytelling.

MiniMax Hailuo 2.3 and 02 deliver exceptionally sharp, detailed output. The 02 version uses an architecture that produces remarkably clean frame transitions—minimal artifacts, smooth motion. For complex physics (synchronized movements, mechanical interactions, intricate choreography), Hailuo competes at the top tier. The efficiency is notable: fast generation without sacrificing quality.

Wan 2.5 specializes in audio-visual synchronization, matching voice, sound effects, and music to visuals in a unified generation pass. This matters when you’re building complete scenes requiring tight coordination between sound and image.

The Seedance 1.0 variants (Pro, Fast, Lite) offer speed-versus-quality tradeoffs for rapid iteration. PixVerse 5 handles style consistency through custom seeds, maintaining a specific artistic aesthetic across your entire trailer. When your book has a distinctive visual identity that needs to remain constant, PixVerse locks it down.

Long story short, none of them is “the best.” Each serves a purpose and in a given video composed of multiple shots you’ll likely want to mix-and-match several different models to get what you need.

Here’s how I plan on utilizing these models for future promo videos:

Runway Gen-4 is for when I need my protagonist’s face consistent across narrative beats—establishing shot, reaction shot, action shot, all maintaining the same character. I’ll turn to Kling 2.5 for dynamic space sequences: ship-to-ship combat, atmospheric entry, anything requiring dramatic camera work and high-speed motion. Veo 3 comes into play when adding dialogue snippets or atmospheric sound design that carries emotional weight. I’ll be using Sora 2 for scenes demanding believable physics—zero-gravity maneuvering, debris impacts, athletic action that needs to feel grounded in reality despite the fantastical setting. And finally, I’m going to lean on PixVerse 5once I’ve established visual style, ensuring every subsequent shot maintains that aesthetic.

Essentially you need to match the primary requirement of each shot to a given model’s specialty. It’s important to understand these are components in the creative pipeline, not complete solutions. Each model has its strength. The trick is knowing which strength each moment in your video actually requires.

One warning from experience: don’t let the tech seduce you into making trailers that look like AI demo reels. The goal isn’t to showcase what the models can do—it’s to sell your book. Use the models as tools to execute your creative vision, not as the vision itself. The best AI-assisted trailer still starts with strong storyboarding and clear storytelling goals.

Think of the models as different tools in your toolbox. Sometimes Kling delivers exactly what you need. Sometimes Sora’s physics understanding makes the difference. Sometimes only Runway’s character consistency will work. You won’t know for sure until you generate and compare clips.

But experimentation, and serendipity, is half the fun of content creation with generative AI.