LTX 2.5 Fast

Overview

ltx-2.5-fast/text-to-video is the accelerated text-to-video route in the Lightricks LTX-2.5 video generation family, accessible through the unified HiAPI.ai interface. Enter a prompt describing the scene, motion, camera, and sound, and you get a video clip with native audio. Duration can be selected in seconds, output supports 720p and 1080p, and aspect ratios cover both landscape and portrait. It is suited to developers and content teams that need fast output to validate shot direction and generate short video assets in high-volume batches.

Key Highlights

• Speed-first accelerated route — Positioned as the accelerated version of the LTX-2.5 family, focused on fast output and suited to repeated trial and error during prototyping and high-frequency batch production.
• Video and audio generated in one pass — Native audio is produced alongside the video, so no separate voiceover or sound-effect step is needed.
• Duration and aspect ratio selected as needed — Duration can be chosen in seconds from 2 to 20, with support for two aspect ratios: 16:9 landscape and 9:16 portrait.

Capabilities

Prompt-to-video directly: Describe the scene, motion, camera, and sound in a single prompt, and the model returns a video file directly, skipping the intermediate steps of storyboarding and frame-by-frame production.

Duration control in seconds: Duration can be set in whole seconds from 2 to 20, with a default of 6 seconds, making it easy to precisely control clip length according to platform placement specs or shot pacing.

Selectable resolution and aspect ratio: Output supports 720p and 1080p, and offers 16:9 landscape and 9:16 portrait, so the same prompt can produce content for different display placements.

Synchronized audio toggle: A parameter controls whether native audio is generated with the video; it is on by default, and can be turned off when no sound is needed to simplify the subsequent editing workflow.

Use Cases

• Rapid validation of shot direction for creative teams — Use short prompts to batch-test shot styles and composition directions, and use the short generated clips as selection samples before deciding whether to expand production.
• Vertical short-video assets for social media operations — Generate assets in 9:16 aspect ratio with shorter durations, ready for vertical placements such as short-video platforms and feed ads.
• Batch output for ads and content — Vary a unified prompt template to generate multiple clips with audio, for multi-version asset testing and high-volume rollout for the same campaign.
• Previsualization for film, TV, and animation — Turn text descriptions from the storyboarding stage into dynamic reference clips with sound, so art and editing teams can assess pacing and atmosphere before formal production.

Limitations and Selection Advice

The accelerated positioning means trade-offs between speed and visual specifications; very long durations and high resolution should not be pursued at the same time. This route has a maximum resolution of 1080p, a maximum duration of 20 seconds, and offers only 16:9 and 9:16 aspect ratios. For final output requiring higher definition or finer quality control, evaluate the Pro version or the image-to-video route in the same family; this route is better suited to prototype validation and high-volume rollout needs.