Determining where to set and modify keyframes

You can freely change any keyframe attribute. Because After Effects provides more than one view of a keyframe, where you modify it depends on what you want to do as well as the type of keyframe and layer property. All layer properties are temporal--they can change the layer over time. Some layer properties, such as Position, are also spatial--they can move the layer across composition space. You modify some attributes of a spatial layer property in different windows than you do temporal properties. (See Comparing interpolation methods.)

Before you make any changes to a keyframe, make sure that the current-time indicator is positioned at an existing keyframe. If you change a property value when the current-time indicator is not at an existing keyframe, After Effects adds a new keyframe. However, if you double-click a keyframe to modify it, the current-time indicator location is not relevant, nor is it relevant when you change a keyframe's interpolation method. (See Comparing interpolation methods.)

Note: You can also copy and paste keyframes into a tab-delimited spreadsheet application, such as Microsoft Excel, and modify the values. This method works for all keyframe types except masks and some effects properties.