LTX-2.3 Is a Free AI Video Generator That Creates 4K Video with Audio — Here’s How to Use It

If you’ve been paying for AI video generators that spit out silent clips you then have to score separately, Lightricks just changed the game. The LTX-2.3 AI video generator dropped in March 2026, and it’s the first open-source model that generates synchronized video and audio in a single pass — at up to 4K resolution and 50 frames per second. No API lock-in. No monthly subscription required. You can run it on your own GPU.

For solo creators grinding out Shorts, Reels, and TikToks, that’s a meaningful shift. Here’s what it actually does, how it compares to the paid options, and how to start using it today.

Table of Contents

• What Is the LTX-2.3 AI Video Generator?
• Why Creators Should Care
• How to Use LTX-2.3: Three Ways to Get Started
• LTX-2.3 vs Kling 3.0 vs Runway Gen-4.5
• Real Creator Workflows with LTX-2.3
• What LTX-2.3 Can’t Do Yet
• Frequently Asked Questions
• Start Generating Video with Audio Today

What Is the LTX-2.3 AI Video Generator?

LTX-2.3 is a 22-billion-parameter Diffusion Transformer model built by Lightricks, the company behind Facetune and LTX Studio. Unlike closed models from Runway or OpenAI, LTX-2.3 is fully open source — the weights are on Hugging Face, the code is on GitHub, and you can deploy it however you want.

The headline feature: it generates video and audio together. Previous open-source video models gave you silent footage. You’d then need a separate tool like ElevenLabs for voiceover or Suno for a music bed. LTX-2.3 handles both in one forward pass, producing clips up to 20 seconds long with sound that actually matches what’s happening on screen.

It supports three generation modes:

• Text-to-video — describe a scene, get a clip with audio
• Image-to-video — upload a still, animate it with sound
• Video-to-video — restyle or extend existing footage

Why Creators Should Care

4K Video at 50 FPS with Native Audio

Most AI video generators top out at 1080p with inconsistent frame rates. LTX-2.3 pushes to true 4K at 50 FPS. The rebuilt variational autoencoder preserves fine textures — hair detail, fabric patterns, even small text renders more cleanly than previous versions.

The native audio isn’t an afterthought either. Lightricks upgraded the vocoder with filtered training data, so ambient sounds, music, and speech come through cleaner than the muddy output you’d get from bolting a separate audio model onto silent video.

Portrait Mode for Shorts, Reels, and TikTok

Here’s what matters for short-form creators: LTX-2.3 natively generates vertical video at 1080×1920. No more generating a landscape clip and awkwardly cropping it. You set 9:16 as your aspect ratio and the model composes the scene for portrait from the start.

That alone saves a step in every short-form workflow. When you’re producing daily content, those minutes add up fast.

Open Source Means Free and Customizable

The model runs under a permissive license. You can use it commercially without per-clip fees. You can fine-tune it with LoRA adapters to match your brand’s visual style — imagine training it on your existing b-roll so generated clips feel consistent with your channel.

Lightricks provides an official LoRA trainer in their GitHub repo, so you don’t need to hack together training scripts. The IC-LoRA variant even lets you separate motion control from visual style, which is powerful for creators who want consistent character movement across videos.

How to Use LTX-2.3: Three Ways to Get Started

Option 1: Cloud API (Fastest)

If you want results in minutes without any setup, the fal.ai API is the easiest path. Install the SDK, grab an API key, and you’re generating in three lines of code. Cost runs about $0.04 per second of generated video.

For a 10-second clip, that’s $0.40 — dramatically cheaper than Runway’s per-generation pricing. If you’re producing a few clips per day for social content, you’re looking at under $15/month.

Option 2: ComfyUI (Most Flexible)

For creators who want full control, ComfyUI is where LTX-2.3 really shines. The official custom nodes ship with reference workflows for every generation mode.

The multi-stage latent upscaling workflow is especially useful: it generates at lower resolution first to nail the motion and composition, then upscales in latent space and runs a second denoising pass for sharp detail. You get better quality than a single-pass generation at full resolution.

ComfyUI also lets you chain LTX-2.3 with other models. Generate a character in Midjourney, use it as an image-to-video input in LTX-2.3, then pipe the output through an upscaler. Modular workflows like this are how pros get results that look polished enough for client work.

Option 3: Local with LTX Desktop

Lightricks offers LTX Desktop for creators who want a simple GUI without nodes or code. Download it, point it at the model weights, and generate through a clean interface.

Hardware requirements: you need at least 12 GB of VRAM (an RTX 3060 minimum). For comfortable 1080p generation, 16 GB+ is recommended — an RTX 4070 Ti or better. 4K generation will push you toward 24 GB cards like the RTX 4090.

If you already have a GPU for gaming or editing, you likely have enough horsepower to run this. The model is roughly 18x faster than Wan 2.2 at equivalent quality settings, so generation times are reasonable even on mid-range hardware.

LTX-2.3 vs Kling 3.0 vs Runway Gen-4.5

Here’s how the three leading options stack up for creators:

The honest take: Kling 3.0 and Runway Gen-4.5 still edge out LTX-2.3 on perceptual quality and motion realism. On community leaderboards, Kling leads with an Elo of 1,244 versus LTX-2.3’s lower ranking. You’ll notice the difference in complex human motion and facial expressions.

But LTX-2.3 wins on cost, flexibility, and the audio integration. For b-roll, product shots, social content, and atmospheric clips — the stuff most creators actually need daily — the quality gap is small enough that free-and-flexible beats expensive-and-marginally-better.

Real Creator Workflows with LTX-2.3

Here are three practical ways creators are already putting LTX-2.3 to work:

YouTube B-Roll Machine. Write a detailed prompt describing the scene you need — “aerial drone shot of a misty forest at sunrise, birds chirping, gentle wind” — and generate 10-second b-roll clips with matching ambient audio. Stack a few of these between talking head segments and your production value jumps without hiring a videographer.

Short-Form Content Pipeline. Set the aspect ratio to 9:16, feed it a product image, and generate a dynamic product reveal with sound design baked in. Upload straight to TikTok or Reels. At $0.40 per clip via API, you can test dozens of variations to find what hooks viewers.

Brand Asset Generator. Fine-tune a LoRA on your brand colors, typography style, and visual aesthetic. Every generated clip then matches your channel’s look. This is where AI-powered creative tools are heading — personalized generation that maintains brand consistency without a design team.

If you’re building a creator business around AI-powered storefronts or digital products, LTX-2.3 gives you a way to produce promotional video at near-zero marginal cost.

What LTX-2.3 Can’t Do Yet

No tool is perfect, and you should know the limitations before diving in:

Complex human motion still stutters. Dance sequences, sports footage, and intricate hand movements can look unnatural. For these, Kling 3.0’s multi-shot consistency is still the better choice.

Audio quality varies. The synchronized audio works well for ambient sounds and simple music, but speech generation isn’t reliable enough for dialogue-heavy content. You’ll still want ElevenLabs or a real mic for voiceover.

LoRAs don’t transfer from LTX-2. If you trained custom LoRAs on the previous version, they need to be retrained for the 2.3 latent space. The architecture changed enough that old weights won’t load cleanly.

Hardware bar isn’t trivial. While 12 GB VRAM is the minimum, you realistically want 16 GB+ for a smooth experience. Creators on laptops with integrated graphics will need to use the cloud API.

Frequently Asked Questions

Is LTX-2.3 really free to use?

Yes. The model weights and code are open source under a permissive license. You can download them from Hugging Face and run locally at zero cost. Cloud API services like fal.ai charge per-second fees (~$0.04/sec), but running locally on your own GPU is completely free for both personal and commercial use.

What GPU do I need to run LTX-2.3 locally?

The minimum is 12 GB of VRAM — an NVIDIA RTX 3060 or equivalent. For 1080p generation at comfortable speeds, 16 GB or more is recommended (RTX 4070 Ti or better). For 4K output, you’ll want a 24 GB card like the RTX 4090. AMD GPU support is limited; NVIDIA CUDA is the primary target.

Can I use LTX-2.3 for commercial content?

Yes. The open-source license permits commercial use. You can generate content for YouTube, client projects, product marketing, and paid courses without licensing fees or watermarks. There’s no per-clip cost when running locally.

How does the audio generation work?

LTX-2.3 generates audio and video simultaneously in a single model pass. It analyzes the visual content being generated and produces matching sound — ambient noise, environmental audio, simple music. The quality is best for atmospheric and environmental sounds. For speech or complex music, you’ll get better results pairing LTX-2.3 video with dedicated audio tools.

How does LTX-2.3 compare to the AI video generators in our roundup?

LTX-2.3 is the strongest open-source option available right now. Compared to the tools in our best AI video generators roundup, it trades some motion quality for zero cost, native audio, and the ability to run entirely on your hardware. For creators who need volume over perfection, it’s the clear pick.

Start Generating Video with Audio Today

LTX-2.3 isn’t going to replace a cinematographer or a sound designer on a high-budget project. But for the daily grind of content creation — b-roll, social clips, product videos, atmospheric intros — it’s the first tool that handles both video and audio in one shot without charging you per clip.

Here’s your next move: if you have a GPU with 12+ GB VRAM, grab the weights from Hugging Face and run a test generation in ComfyUI. If you’re on lighter hardware, sign up for fal.ai and generate your first clip via API in under five minutes.

The open-source AI video space just got its first serious contender that sounds as good as it looks. The creators who learn these tools early are the ones who’ll have an edge when everyone else catches on.