# What is a keyframe?

> A keyframe marks a value, such as size or volume, at one moment, and the editor fills in the rest. See a worked example and common uses in video ads.
- **Author**: Marxx
- **Published**: 2026-11-09
- **Category**: Video editing
- **URL**: https://marxx.ai/library-glossary/keyframe

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A keyframe marks a value, such as size, position, opacity or volume, at one point in time. You set two or more, and the editor fills in everything between them.

## The formula

Change per second = (end value − start value) / seconds

## A worked example

Say you want a slow zoom on a product shot. You set scale to 100% at 0 seconds and 112% at 4 seconds.

(112 − 100) / 4 = **3 points per second**

At 2 seconds the scale reads 100 + 2 x 3 = **106%**. You set two keyframes and the editor draws the rest.

## Common uses

| Property | Keyframe at start | Keyframe at end | Result |
|---|---|---|---|
| Scale | 100% | 112% | Slow zoom in |
| Opacity | 0% | 100% | Fade in |
| Position | Off screen | In place | Slide in |
| Volume | Full | Lowered | Music dips under a voice |

## Keyframes in tools

In Premiere Pro (now called Adobe Premiere), speed changes use keyframes too. Ctrl-click (Windows) or Command-click (macOS) the speed band to add one. Then drag a keyframe's Bezier handles for a smooth change (Adobe Help, checked 3 Nov 2026). That is how a [speed ramp](/glossary/speed-ramp) is built. Premiere's ducking also writes volume keyframes. See [audio ducking](/glossary/audio-ducking).

Marxx's [AI video editor](/features/ai-video-editor) lets you edit by hand with keyframes, including volume and fades. It also has motion presets for entrances, exits, punch-ins and shake, if you do not want to set them yourself. We make Marxx.

A [mask](/glossary/video-mask) can use keyframes too, to grow or move with the shot.

## FAQ

### How many keyframes do I need?

Two: one at the start and one at the end. Add more for a change that has several stages.

### What is easing?

Easing makes a change start or end slowly instead of at a steady rate. Premiere's Bezier handles do this for speed keyframes.

### How do I remove a keyframe?

In Premiere, select the keyframe and press Delete. Other editors have a similar command.

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