how to add keyframe in after effects

Keyframes are used to set parameters for motion, effects, audio, and many other properties, usually changing them over time. A keyframe marks the point in time where you specify a value for a layer property, such as spatial position, opacity, or audio volume. Values between keyframes are interpolated. When you use keyframes to create a change over time, you typically use at least two keyframes—one for the state at the beginning of the change, and one for the new state at the end of the change.

When the stopwatch is active for a specific property, After Effects automatically sets or changes a keyframe for the property at the current time whenever you change the property value. When the stopwatch is inactive for a property, the property has no keyframes. If you change the value for a layer property while the stopwatch is inactive, that value remains the same for the duration of the layer.

When the stopwatch is active for a specific property, After Effects automatically adds or changes a keyframe for the property at the current time whenever you change the property value.

To activate the stopwatch and enable keyframing, do one of the following

Add a keyframe without changing a value

To turn auto-keyframe mode on, choose Enable Auto-keyframe from the Timeline panel menu. When Auto-keyframe mode is enabled, modifying a property automatically activates its stopwatch and adds a keyframe at the current time.

Auto-keyframe mode doesn't automatically activate the stopwatch for properties that aren't interpolated, such as menus, checkboxes, and the Source Text property.

Auto-keyframe mode is off by default. When Auto-keyframe mode is off, modifying properties and animating with keyframes behave as in previous versions of After Effects.

Move the current-time indicator (CTI) to a keyframe

After you set the initial keyframe for a property, After Effects displays the keyframe navigator. You can use the keyframe navigator to move from keyframe to keyframe or to set or remove keyframes. When the keyframe navigator box is filled with a diamond, the current-time indicator lies precisely at a keyframe for that layer property. When the keyframe navigator box is not filled , the current-time indicator lies between keyframes.

To detach the keyframe navigator from the A/V Features column to function as its own column, choose Column > Keys from the Timeline panel menu.

For instructions for moving the current-time indicator to other elements and times, see Move the current-time indicator (CTI).

In layer bar mode, selected keyframes are blue. Unselected keyframes are gray.

In Graph Editor mode, the appearance of a keyframe icon depends on whether the keyframe is selected, unselected, or semi-selected (another keyframe in the same property is selected). Selected keyframes are solid yellow. Unselected keyframes retain the color of their corresponding graph. Semi-selected keyframes are represented by a hollow yellow box.

To toggle viewing of the free-transform bounding box in the Graph Editor, click the Show Transform Box button at the bottom of the Graph Editor.

The Select Previous/Following Keyframes commands aren't available if more than one keyframe is selected.

When you select one or more keyframes, the keyframe menu becomes available at the bottom of the Graph Editor.

To open the keyframe menu, right-click (Windows) or Control-click (Mac OS) a keyframe.

Value

Displays the value of the selected keyframe. If more than one keyframe is selected, the Display Value command is available, which displays the value of the highlighted keyframe in the selection.

Edit Value

Opens a dialog box in which you can edit the value of the keyframe.

Select Equal Keyframes

Selects all keyframes in a property that have the same value.

Select Previous Keyframes

Selects all keyframes preceding the currently selected keyframe.

Select Following Keyframes

Selects all keyframes following the currently selected keyframe.

Toggle Hold Keyframe

Holds the property value at the value of the current keyframe until the next keyframe is reached.

Keyframe Interpolation

Opens the Keyframe Interpolation dialog box.

Rove Across Time

Toggles Rove Across Time for spatial properties.

Keyframe Velocity

Opens the Keyframe Velocity dialog box.

Keyframe Assistant

Opens a submenu with the following options:

Convert Audio To Keyframes

Analyzes amplitude within the composition work area and creates keyframes to represent the audio.

Convert Expression To Keyframes

Analyzes the current expression and creates keyframes to represent the property values it describes.

Easy Ease

Automatically adjusts the influence into and out of a keyframe to smooth out sudden changes.

Easy Ease In

Automatically adjusts the influence into a keyframe.

Easy Ease Out

Automatically adjusts the influence out of a keyframe.

Exponential Scale

Converts the rate of change in scale from linear to exponential.

RPF Camera Import

Imports RPF camera data from third-party 3D modeling applications.

Sequence Layers

Opens the Sequence Layers assistant.

Time-Reverse Keyframes

Reverses selected keyframes in time.

Delete or disable keyframes

To delete any number of keyframes, select them, and then press the Delete key.
To delete one keyframe in the Graph Editor, Ctrl-click (Windows) or Command-click (Mac OS) a keyframe with the Selection tool.
To delete all keyframes for one layer property, click the stopwatch button to the left of the name of the layer property to deactivate it.
When you click the stopwatch button to deactivate it, keyframes for that property are permanently removed and the value of that property becomes the value at the current time. You cannot restore deleted keyframes by clicking the stopwatch button again. Deleting all keyframes does not delete or disable expressions.
To temporarily disable keyframes for a property, add an expression that sets the property to a constant value. For example, you can add this very simple expression to the Opacity property to set it to 100%: 100.

Click the Enable Expression button to toggle the expression on and off, which toggles the keyframes off and on as a side effect.

If you accidentally delete keyframes, choose Edit > Undo.

Jeff Almasol provides a script on his redefinery website that automatically removes keyframes based on specified criteria—for example, all keyframes in the work area, all odd-numbered keyframes.