You can use the Navigate, Zoom, Pan & Zoom, and Frame tools (available from the View menu, toolbar icons, and supra keys) to view a specific area of the graph.
To deactivate any viewing tool, press Esc or choose another tool.
Interactively increase or decrease the magnification of the graph by choosing View 
Interactive Zoom Tool, pressing the C key, or clicking the Zoom icon in the toolbar. The cursor turns into a small magnifying glass:
To zoom in (increase magnification), drag in the graph to define a region to enlarge, or hold down the left mouse button.
The region you draw defines the center of the region you want to see.
To zoom out (decrease magnification), Shift+click and drag. Drawing a larger region zooms out less while drawing a smaller region zooms out more.
To interactively increase and decrease the height of the view, right-click and drag up and down.
To increase and decrease the width of the view, right-click and drag right and left.
You can also zoom in and zoom out by choosing View Pan and Zoom Tool, clicking the Pan icon in the toolbar, or pressing the Z key.
To zoom in, hold down the middle mouse button. The zoom-in continues until you release the mouse button.
To zoom out, hold down the right mouse button. The zoom-out continues until you release the mouse button.
To pan, drag with the left mouse button. The pan continues until you release the mouse button or the Z key.
By default, you can zoom using the mouse wheel:
If desired, you can disable the mouse wheel zoom or restrict it to the Navigation tool so that you can use the mouse wheel with other tools. See Mouse Wheel in Camera Preferences [Preference Reference].
You can pan to scroll the area shown in the graph by choosing View Pan and Zoom Tool, clicking the Pan icon in the toolbar, or pressing the Z key.
You can pan and zoom in the graph in any direction, including in constrained directions. You can use a number of different tools to pan and zoom in different ways.
Choose View Navigate Tool, press the S key, or click the Navigate icon in the toolbar.
To interactively pan the view, left-click and drag the mouse pointer in the graph.
To pan in a constrained direction, press Shift and left-click and drag in that direction.
To interactively zoom in, middle-click and drag to the left; to zoom out, middle-click and drag to the right.
To interactively zoom only horizontally, press Shift and middle-click and drag to the left to zoom in, and drag to the right to zoom out.
To interactively zoom only vertically, press Shift and middle-click and drag down to zoom in, and drag up to zoom out.
Framing sets the zoom and pan so that the curves or keys fit in the graph within a specified range.
Select the keys and choose View Frame Frame Selection, click the Frame icon, or press the F key. If no keys are selected, the selected curves or regions are framed.
To automatically frame all fcurves in the graph
Choose View Auto Frame Curves. This applies when you open the animation editor with a selected object and when you update the selection.
If you have the View Selected Parameters filter active and you select one or more parameters in the animation explorer, their fcurves are automatically framed in
the graph.
You can set a default preference for whether Auto Frame Curves is on or off in the Fcurve Editor Preferences property editor.
Choose View Frame Selected Curves or Selection, click the Frame icon, or press the F key. If nothing is selected, then all curves are framed.
To frame all the fcurves within the time span specified by the timeline
To center the fcurve graph around the timeline cursor's position
Make sure that the timeline cursor is visible in the fcurve editor. Then move the timeline cursor where you want it (in either
the scene's timeline or the fcurve editor's timeline) and choose View Frame Center Current Timeline,
If there are frames displayed that go out of the range of those defined by the scene's timeline, that part of the graph is displayed with a darker gray.
