First / Last Frame-to-Video (FLF2V)

First / Last Frame-to-Video (often abbreviated as FLF2V) is an interpolation-based AI video generation workflow. Rather than asking the model to invent both the beginning and the end of a scene, users explicitly provide the first frame and the final frame, while LTX 2.3 generates all intermediate frames.

This approach gives creators considerably more control over the resulting animation. The model understands the visual relationship between both keyframes and predicts a smooth sequence of motion that connects them while preserving temporal consistency.

Unlike Image-to-Video, which starts from only a single reference image, FLF2V constrains both ends of the animation. This makes it particularly useful for storytelling, cinematic transitions, product reveals and scenes where the ending composition is just as important as the opening shot.

The workflow begins with two user-provided images: the first frame and the final frame. These keyframes define the visual boundaries of the animation.

LTX 2.3 analyzes both images to identify subjects, composition, perspective, lighting and scene structure before generating the intermediate motion. During inference, the model predicts how objects, characters and the camera should move in order to transition naturally from the first image to the last.

An optional text prompt can provide additional creative guidance by describing the desired movement, pacing, atmosphere or cinematic style. However, unlike Text-to-Video, the overall composition is largely determined by the supplied keyframes, making the output much more predictable and controllable.

Because creators explicitly define both endpoints of the animation, FLF2V is particularly valuable for controlled production workflows.

Typical use cases include:

• cinematic scene transitions
• before-and-after visualizations
• product reveal animations
• architectural presentations
• character transformations
• concept art animation
• storytelling sequences
• logo animations
• creative advertising

The workflow is especially attractive for filmmakers and designers because it provides significantly more creative control than purely prompt-based generation while requiring far less manual animation than traditional video production.

Advantages

• Strong control over both the start and end of the animation.
• Highly predictable results.
• Excellent temporal consistency.
• Natural scene interpolation.
• Suitable for professional production workflows.

Limitations

• Very different keyframes can produce unrealistic transitions.
• Complex scene changes may require multiple attempts.
• Motion remains model-generated rather than manually animated.
• Careful selection of keyframes significantly improves results.

The more visually related the first and last frame are, the easier it is for the model to generate believable motion between them.

Successful FLF2V workflows depend much more on keyframe preparation than on writing long prompts.

Recommended practices include:

• choose visually consistent first and last frames
• maintain similar lighting between both images
• keep camera perspective relatively stable unless dramatic motion is intended
• avoid unnecessary scene changes
• use prompts to describe movement rather than appearance
• experiment with different transition lengths
• iterate gradually when refining motion

Many professional creators first design both keyframes before generating the interpolation, allowing them to maintain creative control throughout the production process while minimizing the amount of manual editing required afterward.