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Glossary · Video Generation

What Are Start Frame & End Frame in ComfyUI?

By Earngenix Team ·

⚡ Quick Answer

Start Frame and End Frame are two reference images you give a video workflow to define exactly how the clip begins and ends. Instead of the model improvising everything after a single starting image, it generates the motion that connects your two chosen pictures.

This gives you far more control over the outcome than ordinary image-to-video, where only the beginning is fixed and everything after is up to the model.

Where You'll See It

Two separate Load Image nodes feed into a video workflow, typically labeled something like start_image and end_image. This is a feature of specific workflows and models — not every video model supports it.

Quick Example

Supplying a photo of a folded cardboard box as the start frame and a photo of the same box fully assembled as the end frame lets the model generate a believable assembly animation connecting the two.

The two images should show a reasonably related scene or subject. A start and end frame that are wildly different from each other often produces strained or unnatural-looking motion as the model tries to bridge the gap.

Frequently Asked Questions

They should match, or at least share the same aspect ratio. Mismatched dimensions usually get cropped or resized automatically, which can shift your framing in ways you didn’t intend.

No — it needs a model and workflow specifically built to accept two reference images, like FramePack-based workflows. A standard image-to-video setup only takes one starting image.

The model still tries to generate a transition, but the result can look strained or add unexpected motion to bridge a large visual gap. Start and end images that are reasonably related to each other tend to produce cleaner results.

See It In Action

Ready to control both ends of a clip?

Our FramePack guide covers the full start/end frame setup.

Published: 2026-09-17 · Last updated: 2026-09-17

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