Load Frame Interpolation Model

Load Frame Interpolation Model is the node that puts new frames between existing ones. It loads a frame-interpolation model from ComfyUI/models/frame_interpolation and hands you an INTERP_MODEL wire, which feeds the Run Frame Interpolation Model node - the thing that turns a 30fps clip into 60fps, or turns a short video into dramatic slow motion. If you've ever wanted AI-generated intermediate frames to smooth out motion, this is the loader at the front of that pipeline. The tooltip is the manual: "Models must be placed in the 'frame_interpolation' folder."

How it works

One input, model_name. The loader reads the file and auto-detects what kind of interpolation model it is - and this is where the node quietly punches above its weight, because it accepts the two main families:

• FILM (Google's Frame Interpolation for Large Motion) - recognized by its extract.extract_sublevels weight structure.
• RIFE / IFNet - the community standard for realtime-interpolation, recognized and loaded through the IFNet path with automatic key remapping for raw checkpoints.

So the same loader serves both families, and you don't tell it which - it sniffs the weights and loads the right network, then hands you an INTERP_MODEL. The consuming node, Frame Interpolate, takes the model, your image sequence (frames of a video), and a multiplier (2 to 16). A multiplier of 2 doubles the frame count; higher values synthesize proportionally more intermediate frames. If your input has fewer than 2 frames or the multiplier is below 2, it passes the sequence through untouched.

Why you'd reach for it

Three jobs, all of which are real:

1. Slow motion. Interpolate a 2x or 4x frame count and stretch the timeline - the model invents the in-between motion rather than duplicating frames.
2. Frame-rate conversion. Smooth a 24fps generation up to 48 or 60fps so motion looks natural instead of stuttery.
3. Video work after generation. Video models output at fixed frame counts; interpolation is how you extend, retime, or smooth their results in post. This is the "more pixels over time" rung of the upscaling ladder, distinct from both pixel upscalers and generative restorers.

Gotchas

• The folder is frame_interpolation, not upscale_models. RIFE files get dumped in the wrong place constantly, then the dropdown is empty and the panic sets in. It's a one-word fix.
• The model must be a supported family. FILM and RIFE/IFNet are the two it knows. A newer or exotic interpolation architecture that doesn't match either fingerprint will fail the detection with an "unrecognized format" error rather than a helpful hint.
• Interpolation isn't free of artifacts. Fast, complex motion is where synthesized frames get mushy or warp - FILM handles large motion better, RIFE is faster. Pick the family for your footage.
• It doesn't create motion that isn't there. Interpolation assumes the motion between A and B is continuous. It's a smoothing tool, not a content generator.

It ships with ComfyUI core - no install. One of the more niche loaders in the category, but if your workflow touches video and you've ever wanted buttery slow motion, it's the missing piece.