LTX 2.3 Fast
The longest 4K clips on Stensyl. Up to 20 seconds at 1080p / 2K / 4K, lowest cost per second.
LTX 2.3 Fast is the long-duration variant of Lightricks' 22-billion parameter open-source model. Same architecture, faster inference, an extended duration ceiling of 20 seconds, and the full resolution range — 1080p, 2K, or 4K. The only model on Stensyl that combines long-form duration AND 4K output in a single call. Ideal when you need a clip longer than the 6–10s caps of Pro models, or when you're iterating in bulk before committing to a flagship render.
Example outputs
“A dog sprinting across a park and leaping to catch a frisbee, landing and trotting back proudly, sunny day, playful energy”
“A matte black concept car drifting through an empty underground car park, tyres smoking, neon strip lights reflecting off the wet concrete floor, cinematic low angle”
“A fantasy warrior charging across a burning bridge toward a collapsing fortress, debris flying, dramatic wide shot, epic game cinematic trailer”
“A time-lapse of a sunset over city rooftops, clouds streaking across the sky, street lights flickering on one by one below”
“A butterfly gliding in and landing on a flower, wings slowly folding closed, macro close-up, soft garden light”
“A basketball spinning on a fingertip then tossed upward, camera following it in dramatic slow motion, dark gym, single spotlight”
How it works
Describe your scene
Type a detailed prompt describing the video you want, or upload a reference image as a starting frame.
Choose your settings
Pick your resolution and duration. See the credit cost before you generate.
Generate your video
Your video is ready in 1-3 minutes. Download, iterate, or extend the sequence.
Ready to create with LTX 2.3 Fast?
Jump into the Studio and start generating. Plans from £10/month.
The longest 4K clips on the platform.
LTX 2.3 Fast reaches 20-second video at 1080p, 2K, or 4K with native audio. Every other flagship model on Stensyl tops out earlier on duration — Veo 3.1 at 8 seconds, Kling 2.6 at 10, Seedance 2.0 and Happy Horse at 15 — and most don't reach 4K at all. Fast is the only model that combines both maximums in a single call.
Same 22-billion parameter architecture as Pro, same rebuilt VAE, same one-pass audio generation, same native portrait mode. The trade-off is slightly less fine detail at the pixel level — exactly the right call for sequences where length and rhythm matter more than micro-texture.
Duration steps in 2-second increments — 6, 8, 10, 12, 14, 16, 18, or 20 seconds. Pricing is clean 2× per resolution tier ($0.04 / $0.08 / $0.16 per second at 1080p / 2K / 4K). Pair with Stensyl's Editing Studio (Extend, Retake, Audio-to-Video) to push beyond 20 seconds via clip extension.
Questions about LTX 2.3 Fast.
Why Stensyl?.
Ready to create with LTX 2.3 Fast?
Professional video generation. Plans from £10/month.