Timeline Panel

The time-based heart of the editor: arrange layers in time, scrub and play back, and edit animation. One panel, three modes — Layers, Keys (dope sheet), and Graph — sharing a ruler, playhead, and work area.

The Timeline sits in the bottom-left of the editor. It has a fixed top toolbar (transport + mode switch), a left panel that changes with the mode (layer list / param list), and a scrollable tracks area on the right with a ruler across the top.

Modes

Three modes, switched by the segmented control in the toolbar or by pressing Tab (cycles Layers → Keys → Graph):

Mode	Label	Left panel	Tracks show
Layers	Layers	Layer list (eye / blend / matte)	Clip bars + keyframe diamonds
Dope Sheet	Keys	Param list	Keyframes as a grid of diamonds
Graph Editor	Graph	Param list + Node/Layer/Comp scope	Animation curves

The ruler, playhead, work area, and horizontal view (zoom and scroll position) are shared across all three — switching modes keeps the same range of frames on screen. The left lists share the same row spacing and header height. Keys and Graph share the layer picker and Node / Layer / Comp scope controls; Keys keeps whole-parameter editors, while Graph groups component curves under their nodes.

Toolbar

Left to right:

• Composition settings (gear) — opens the comp dialog (also Cmd+K).
• Go to start — jump the playhead to frame 0.
• Play / Pause (Space) — real-time playback, or RAM-preview playback when RAM mode is on.
• RAM Preview toggle — switch between real-time and cached playback (see RAM preview).
• Time display toggle — switch the playhead readout between frames and timecode.
• Playhead field — the current frame/timecode; click to type an exact value and jump there.
• Work area toggle — set or clear the work area (preview range) to the full comp.
• Mode tabs — Layers / Keys / Graph (or Tab).
• Auto-key toggle (Shift+K) — when ON, editing an animated param auto-creates a keyframe; when OFF, edits are temporary and revert on playhead move.
• Clear cache — resets the caches and re-renders the current frame.
• Zoom out / in — also plain scroll wheel over the tracks (+ / - keys too). The zoom-out range adapts to the composition's duration, so even very long comps can be zoomed out to fit. Fit snaps the view to the whole comp duration in one click. Every zoom — buttons, keys, scroll wheel, pinch, middle-drag — is centered on the playhead: it stays put on screen while the frames scale around it, or moves to the middle of the view if it was off screen.
• Render — opens the export dialog. Also available as File → Export… (Cmd Shift E) — handy on small screens where the toolbar runs out of room, and it works even with the timeline panel closed.

In Layers mode an extra contextual group appears (duplicate selected layers, etc.).

Narrow panels

The toolbar measures its own width (the timeline panel's, not the window's) and folds controls away in two steps, so Render never leaves the bar:

Toolbar width	What changes
under ~1150 px	Zoom out / in / Fit collapse into one Zoom button that opens them in a popover (the scroll wheel and + / - keys keep working). The contextual layer tools (Layers mode) or keyframe tools (Keys / Graph) collapse into a ⋯ button; their keyboard shortcuts (Cmd Shift D split, Cmd Shift R reverse) stay active while collapsed. Work area becomes an icon button — the current range shows in its tooltip.
under ~950 px	The composition selector narrows (long names truncate). Auto-key and Clear cache join the ⋯ popover. The playhead field shows frames only; its frames/timecode toggle steps out with it (the preference is kept and comes back when the panel widens).

Transport, the playhead field, and Render never collapse. See Top Bar for how the bar above the panels behaves.

Layer list (Layers mode)

The left panel lists the comp's layers, topmost first. The divider between it and the tracks is draggable to resize (380–600px, shared by all three modes). Below 460px, the Layers list scrolls horizontally so layer names and switches keep usable space; scroll right to reach the remaining columns and add/delete buttons, or widen the divider. Each row has:

• Eye — enable/disable the layer (hidden layers don't render or composite).
• Lock — freeze the layer against editing. See Locking layers.
• Motion blur — per-layer temporal-supersampling toggle (uses the comp's shutter settings).
• Blend mode — dropdown (Normal / Add / Multiply / Screen / Overlay) setting how the layer composites over the layers beneath it.
• Matte — dropdown to pick a track-matte source layer plus an Alpha / Luminance toggle. The matte source layer is excluded from normal compositing (standard track-matte behavior) and shows an M badge.
• Name — double-click to rename.

Selection

• Click — make the layer active (drives the node graph + Properties) and replace the selection.
• Cmd-click — toggle a layer in/out of the multi-selection.
• Shift-click — range-select from the active layer to the clicked one.
• Marquee — drag on empty track space to box-select.

One layer is active at a time — it's the layer the node graph and Properties panel follow. You can also have several layers selected at once for batch actions like sliding, duplicating, or deleting them together. Clicking a layer (in the list, on its track, or in the node-graph background) also selects its transform, so the on-canvas gizmo, Properties, and node graph all agree on what you're editing.

Precompose selected layers

In Layers mode, select a contiguous block in the stack and click the Precompose icon (layers inside a frame) beside Duplicate in the toolbar's layer tools (⋯ → Layers in a narrow panel). You can also press Cmd+Shift+C (Ctrl+Shift+C on Windows/Linux) from any focused panel while Timeline is open, including Keys/Graph mode with keyframes selected. Copy/Paste Ease use Cmd+Alt+C / V instead. The shortcut is rebindable in Preferences → Shortcuts. Enter a composition name, choose Trim to layer duration (on by default), and confirm. The host stays open with the replacement Comp Source layer selected. Open the new composition from Assets, the composition selector, or the Comp Source node's Open button to edit its original layers. Undo/redo treats the entire move as one step.

The new composition copies the host's size, frame rate and shutter settings. With Trim to layer duration on, it spans the earliest selected in-point through the latest selected out-point, including gaps between layers and any authored tails beyond the host duration. For example, clips spanning frames 30–90 make a 60-frame composition; its replacement occupies 30–90 in the host. Moved clips and every keyframe shift back by 30. Source offsets, key values, easing/tangents, layer/node IDs, stacking, graphs and color tags are retained. Keys before the cut remain at negative frames so interpolation and pre-roll are not lost. Projects containing these keys require a build that supports signed keyframe times.

The trimmed composition has its own zero-based clock and shorter duration. Ordinary keyed animation and Layer-time media keep their host timing. Nodes explicitly using composition time or duration—including Composition-mode media/nesting and absolute/quantized time effects—now use the new context and can change their result. Their parameters are not silently rewritten.

Turn Trim to layer duration off to keep the original full-host clock and duration: clips, keys and offsets stay unchanged, and the replacement spans the full host duration. In either mode, sliding and trimming the replacement subsequently behave like ordinary nested footage.

The replacement's audio is always wired, even if the selected layers are currently silent, so adding or unmuting sound inside works later. Its motion blur starts off to avoid blurring twice; the moved layers retain their own motion blur under the copied shutter settings. The replacement starts untagged and with neutral Output settings.

Safety checks: Precompose refuses a move rather than silently changing its meaning:

• Select an actual contiguous stack block, not just adjacent search results. Locked, missing or foreign layers cannot be moved.
• Selected layers must use Normal Output blending throughout their animation. Blend drivers, Bezier blend-mode keys and adjustment layers are not supported. Ordinary opacity animation, geometry, sound and inner motion blur are supported.
• Keep both ends of Layer Source, Value Source, parenting and track-matte dependencies together. This includes all consumers, not only the producer. Precompose does not expand your selection automatically. Detach/unlink a boundary connection first if you do not want to move its other end.
• Internal publications move with their sources. Internal linked nodes retain their links; links crossing the selection (including consumers in other compositions) are rejected. Linked structural nodes such as Output, Parent and Comp Source must be unlinked first.
• Repair missing references, dangling/cyclic graphs or unsupported animated structural references first. Composition nesting must remain acyclic and within eight levels, including existing ancestors; unresolved or linked Comp Source references must be repaired/unlinked.
• Stop playback, active RAM preview and tracking, finish edit gestures, and turn off Solo first. Confirmation checks the current selection and project again; changing the composition or selection requires reopening the dialog. Cancel makes no project change.

No layers are flattened, cropped to content, or baked.

Locking layers

The padlock freezes a layer so you can't edit it by accident — useful for a background plate or a finished element you keep clicking on while working on something in front of it. A locked layer shows a solid padlock; unlocked layers show a faint open one.

Locking is about selection. A locked layer cannot become the active layer, cannot join a multi-selection, and drops out of the selection the moment you lock it. That one rule is what makes the rest fall out:

• Clicks in the viewer pass straight through it. Clicking where a locked layer sits selects whatever is behind it, rather than hitting the lock and doing nothing — so you can lock a foreground element and keep working on the layer underneath.
• It can't be deleted, and it can't be dragged — neither reordered in the layer list nor slid or trimmed on its track. (It still gets pushed up and down the stack when you move other layers around it; only grabbing the locked layer itself is refused.)

What locking deliberately does not do:

• Its own switches still work. You can toggle the layer's eye, motion blur, audio mute — and the lock itself — without unlocking first. Otherwise you could never get back out.
• It still renders, composites, and plays. Lock is an editing guard, not a visibility or output setting; exports are unaffected.
• Its node graph is still live. Locking blocks selecting the layer, so it won't become the node graph's subject — but if the graph is already open on that layer, everything in it still works.

The lock is saved in the project file, so it survives closing and reopening.

Painting switches down the list

The eye, lock and motion blur columns can be painted: press one switch and drag up or down the list, and every row you pass over takes the same value the first row just took.

• The value is decided once, on the row you start from — it's that row's opposite. Every other row is set to that value, not toggled, so the drag can never flip a row back and forth, and passing over a row twice does nothing the second time.
• Only the column you started in is painted. Sliding sideways into another column has no effect.
• Release anywhere to finish, or press Escape to abandon the drag and put every row back.
• The whole drag is a single undo step, however many rows it covers.

If the row you start from is part of a multi-selection, that first press still applies to every selected layer (as a plain click always has); rows you then drag over are painted one at a time.

Tracks & clips (Layers mode)

Each layer is a clip bar spanning its start → end on the timeline.

• Drag the body — slide the clip in time. Sliding moves the layer's keyframes with it (so the animation travels with the clip).
• Drag an edge (trim) — change the in/out point. Trimming does not move keyframes — it reveals/hides source by adjusting the layer's source offset.
• Extend earlier — the left edge can move back to composition frame 0, even before the layer's original local start. For example, slide an animated layer from frame 0 to 30, then extend its left edge back to 0: the existing keys stay at their slid positions, and you can add earlier keys. A clip always keeps at least one frame.
• Locked layers don't slide or trim — unlock the layer first.
• Keyframe diamonds — animated params show their keyframes as diamonds along the clip.

Keyboard equivalents (timeline focused):

• [ / ] — slide the active (or selected) layers so the in / out point lands on the playhead, preserving duration; keyframes ride along.
• Alt+[ / Alt+] — trim the in / out point to the playhead (duration changes; keyframes stay).

Earlier extension and source timing

Earlier extension preserves the ordinary source clock on frames that were already visible; it does not invent source content before a file starts. Nonlooping video and image sequences hold their end frames, nested comps are blank outside their own duration, and nonlooping audio is silent outside its source. Forward-looping audio wraps before source zero, keeping its playback phase as it crosses into the previously visible frames. Other existing loop mappings still apply.

Some nodes deliberately follow the clip itself: Point Emitter, Point Solver, Point Advect, Point Trail, and Slitscan Scan remain anchored to the visible clip start, so extending earlier can start or rebuild their history earlier and change later results. Time's Frame/Seconds outputs and Noise retain their local-zero holds; Time's Normalized output still depends on clip duration, and Freeze Frame's layer-relative mode still counts from the clip start. Trimming preserves authored key timing, not every time-dependent result.

Panning the tracks

With the Pan tool (H) active, a left-drag anywhere in the track area slides the timeline — through time horizontally, through layers vertically — instead of starting a marquee, a clip slide/trim or a playhead scrub. It works the same in Keys and Graph mode. Middle-drag keeps its existing meaning everywhere: a pan in Keys and Graph, and the time-axis zoom here in Layers. See Canvas Navigation.

Nesting compositions

Drag a composition from the Assets panel onto the tracks to nest it: the drop creates a layer wired Comp Source → Output, named after the composition and trimmed to its duration (converted to this comp's frame rate). The nested comp plays from its first frame at the layer's in-point, so trimming, sliding, and offsetting the clip work exactly like a video clip. Select the layer and use Open next to the Composition picker in Properties to edit the nested comp; changes show up everywhere it is used. If the nested comp has sound, the drop also wires the Comp Source's Audio output into the layer's Output, so its audio plays and exports through the layer, following the clip and the layer's Audio Gain, Pan, and Mute; disconnect that wire to nest the picture alone (no waveform is drawn for nested audio yet). See Comp Source for time modes and clipping rules.

Layers past the comp end

Layers may slide or trim beyond the comp's last frame (capped at 2× the comp duration so the scrollable width stays bounded). Frames past the comp end are dimmed and marked with a thin vertical line through the ruler and tracks. Layers out there are visible on the timeline but render nothing — the comp only renders its own frames, from frame 0 up to its duration. This is what lets [ put a full-length layer's in-point on a playhead deep inside the comp (its tail just spills past the end).

Ruler, playhead & work area

• Ruler — frame ticks and labels across the top; click or drag anywhere on it to scrub the playhead. The label density adapts to zoom.
• Playhead — a vertical line at the current frame; drag its triangle handle to scrub. It stays within the comp, from frame 0 to the last frame.
• Scrub beyond the view — in Layers, Keys and Graph, hold a ruler or playhead-handle drag beyond either visible horizontal edge to pan through time. Panning continues while the pointer is stationary outside; farther outside goes gradually faster, up to a capped speed. It stops at the composition boundary. There is no automatic panning inside the view: bring the pointer back in to scrub the frame directly beneath it. Release, Escape, loss of window focus, or switching modes ends the gesture at its latest position (no animation rollback). Changing composition or zoom also ends it. This does not move keyframes, clips or the work area, and the Pan tool keeps its normal navigation behavior.
• Page Up / Page Down — step the playhead back / forward one frame (global).
• Cache indicator — thin bars under the ruler show which frames are cached, colored by the resolution they were rendered at: green = Full, light blue = 1/2 Preview, gold = 1/4 Draft. RAM preview bars follow the same coding — they show the quality the preview was cached at. The viewer's quality dropdown uses the same colors, so during Auto-quality playback you can see exactly which spans hold which resolution — and why. Picking a manual quality drops cached frames from other tiers so the viewport always shows the resolution you asked for.
• Work area (preview range) — a lighter band on the ruler with drag handles (left/right to resize, middle to slide). The region outside it dims. Sets the range for RAM preview and looped playback. Keyboard:
  • B — set work-area start to the playhead.
  • N — set work-area end to the playhead.
  • The work area always stays clamped inside the comp.

Note: in Keys / Graph mode with keyframes selected, B sets the selected keyframes to Bezier (the H/L/S/B interpolation shortcuts). With no keyframes selected, B sets the work-area start.

Playback & RAM preview

• Real-time — plays at the comp frame rate, rendering on the fly at adaptive (usually Preview) quality. Skips frames to keep up.
• RAM preview — caches frames over the work area at the current viewer quality (Full when idle), then plays them back at native frame rate (4 GB budget). Numpad 0 triggers caching; Space toggles play/pause while keeping the cache. Editing the project resets the RAM preview.

Keys mode (Dope Sheet)

A compact grid of keyframe diamonds, one row per animated param, aligned with the param list on the left (collapsible layer headers).

Parameter scope (Keys and Graph)

• Node — only the selected node, or explicitly selected nodes, in the active layer. Nodes with the same type or name remain separate. The automatically selected layer transform counts as a selected node too.
• Layer — every animated parameter in the active layer.
• Comp — every animated parameter across the active composition, topmost layer first. Search and tag filters in Layers mode do not limit Keys or Graph.

No selected node means an empty Node scope; no active layer means an empty Layer scope. The scope buttons remain available so you can choose a wider view. Keys and Graph remember their scopes separately.

Press J / K to jump to the previous / next keyframe in that scope. Navigation uses all keys in the scope, not just selected rows, selected keys or visible curves. It skips the current frame and stops at the first/last key without wrapping; keys outside the composition's playable range are not navigation targets. These shortcuts work in Keys/Graph while stopped and outside text fields, not in Layers mode.

Click a parameter row to focus it, Cmd/Ctrl-click to toggle rows, or Shift-click for a range in Keys. In Node scope, row clicks preserve the selected nodes so you can work across their parameters without hiding the other rows. In Layer/Comp scope, Keys row clicks also navigate to the source layer/node. Row selection never widens the scope. When the scope or selected nodes change, parameter rows that leave the list also leave the row selection, so they cannot remain hidden paste targets. Surviving row selections stay selected. Selected keyframes and the copied keyframes are kept separately, so copying from one node and then selecting another can still retarget a paste.

Values and keyframes

Keys labels show Node / Parameter in Node and Layer scope, since the layer is already named in the dropdown. Comp scope retains layer context in the row label or grouped layer header.

Keys shows the value at the current playhead beside each parameter name, including between keys. Ordinary numbers, vector components, numeric dropdowns and checkboxes can be edited here with the same controls as Properties. Click a label to select its row; interacting with a value control leaves row, node and keyframe selection alone.

• Edits affect the playhead, not the selected keys. An animated parameter inserts or updates a key at the playhead even with Auto-Key off; other keys are retained. Merely focusing a field does not add a key.
• Numbers support live typing, arithmetic on commit, and horizontal scrubbing with the usual precision modifiers. Vector links work as in Properties; an unlinked component edit preserves the other components' interpolated values.
• Undo groups a typing session or continuous scrub into one step. Enter/blur finishes typing; Escape cancels the current edit, including a newly inserted key. An unrelated edit or undo ends that undo group. Changing frame, scope or layer, or removing the control, finishes the live changes already made and stops the gesture.
• Driven/linked parameters show a read-only link indication, not a misleading authored value presented as the driver's result. Editing is disabled during playback, active RAM preview, and on locked layers.
• Specialized editors (including colors, strings, ramps, paths, track lists, dB/font controls, Levels, Curves and Shader parameters) retain a compact authored-value summary and an explicit Edit in Properties button. That button navigates to the source node and opens Properties; it does not change the value. Large editors do not expand the track rows.

Value displays and summaries describe authored animation, not engine-resolved outputs. Hover a summary for its frame and description.

Hover a keyframe in Keys or Graph for its frame and stored value — not the playhead value. Graph vector/color tooltips identify the component; path keys show a path summary. In the Speed graph, the tooltip still describes the key's parameter value, not velocity.

• Select keyframes by clicking or marquee; a selection box around 2+ keys can be dragged to slide them or edge-handled to scale their timing.
• Interpolation of selected keys: H Hold · L Linear · S Smooth · B Bezier.
• Handle mode of selected keys: 1 Auto · 2 Clamped · 3 Free.
• Copy / Paste — Cmd/Ctrl C copies the selected keyframes (or, with a param row selected and no keyframes, the row's whole keyframe set); Cmd/Ctrl V pastes with the earliest key landing on the playhead, relative offsets preserved — including offsets between params when keys from several params were copied. Also available from Edit → Copy / Paste and the keyframe right-click menu ("Paste at Playhead").
• Where a paste lands — keyframes travel between like-type nodes. With nothing else selected they paste back onto their own params. Select a different layer (or several) and the keys land on the matching parameter of the same node type there — position from one Transform 2D onto another layer's Transform 2D, a Blur radius onto another layer's Blur. Select nodes in the node graph and each selected match receives the keys. Select param rows in the list and the rows are the targets: a row with the same parameter takes it, and when a single param was copied any row of the same value type does too (position onto scale). Rows of a different value type are left alone. Pasted keys are selected afterwards, and the whole paste is one undo step.
• Copy Ease / Paste Ease — Cmd/Ctrl Alt C copies only the easing of the selected keyframes (interpolation, handle mode, in/out bezier handles); Cmd/Ctrl Alt V applies it to the selected keyframes, in frame order, repeating a copied pair across every selected pair. Values and timing are untouched, so one hand-tuned ease can be stamped across any number of curves. Auto handles are copied as the shape they resolve to.
• Right-click selected keyframes for a context menu: interpolation, Copy, Paste at Playhead, Copy Ease, Paste Ease, ease presets (and Delete in the graph editor).
• Delete / Backspace removes selected keyframes.
• Keyframes can sit at or beyond the end of the clip/comp — drag them onto (or past) the clip boundary; values past the last keyframe hold, and data beyond the end survives if the clip is later extended.

Graph mode (Graph Editor)

An SVG curve view of animated parameters.

• Left panel scope — the same Node / Layer / Comp rules as Keys. Click a parameter to show its curves; Cmd/Ctrl- or Shift-click to extend the curve selection. The eye toggles visibility.
• Curves — every visible param is a colored curve; the active param's curve is slightly thicker. Colors default by component (X red, Y green, etc.); click the swatch next to a curve in the left panel to recolor it from the tag palette (or Default to restore the automatic color). Saved with the project.
• Keyframes — drag to move (frame + value); double-click empty space to add one; marquee to select.
• Tangent handles — selected Bezier keyframes show in/out handles you can drag. Handle modes: Auto (Catmull-Rom), Clamped (auto, Y-clamped), Free (manual). Bezier is symmetric — a segment eases if either endpoint is Bezier, and each endpoint contributes its own handle.
• Joined handles — a keyframe's in and out handles are joined by default: drag one and the other rotates to keep the curve smooth through the key, keeping its own reach into its segment. Hold Alt/Option while dragging to split them and move one side on its own; the split sticks to that keyframe (its handle dots turn into hollow squares) so later drags keep moving one side. Join Handles / Split Handles in the right-click menu do the same without dragging; setting a key back to Auto or Clamped (1 / 2) also rejoins it. On a flat segment (both keys at the same value) the handle on that side stays flat — it can't tilt to follow the other side.
• Multi-key handle drag — with several keyframes selected, dragging one handle applies the same change to the same-side handle of every selected Bezier key, measured relative to each key's own segment, so a batch of eases moves together whatever their value ranges.
• Ease presets — a menu applies Identity / Ease In / Ease Out / S-curve to the selection.
• Copy Ease / Paste Ease — Cmd/Ctrl Alt C / V (also in the right-click menu) copies the selected keys' handles and interpolation and stamps them onto other selected keys, per pair. See Keys mode above.
• Vertical zoom — Alt+scroll zooms the value axis; the value-scale edges can be dragged.

Value / Speed

A Value / Speed toggle (top-left, matching the scope selector) switches the Y axis:

• Value — the parameter's value over time (the normal curve).
• Speed — how fast the parameter is changing (its velocity), drawn as a curve with a shaded "hill" beneath it. The Y-axis label and a clearly-filled toggle indicate which mode you're in.

In Speed mode, selected Bezier keyframes show velocity handles: drag vertically to set the speed at that keyframe, horizontally to set the influence (how far the ease reaches into the segment). These map straight back to the same Bezier tangents the Value graph edits, so the two views stay in lockstep. Joined handles hold here too: dragging one side's speed carries the other side with it (a joined key has one speed through it), Alt/Option splits, and a multi-key selection drags together. The speed=0 baseline floats just above the bottom edge so at-rest handles stay easy to grab. Keyframe markers in Speed mode are select-only — retiming and adding keyframes are Value-graph operations.

Reverse keyframes

The toolbar's reverse action mirrors the selected keyframes' timing around their own range (first ↔ last), reversing the motion.

Keyboard shortcuts

The timeline shortcuts (and all others) live in docs/keyboard-shortcuts.md. Quick reference:

Key	Action
Tab	Cycle Layers / Keys / Graph
Space	Play / pause
Page Up / Page Down	Step playhead back / forward one frame
[ / ]	Slide layer in / out point to playhead
Alt+[ / Alt+]	Trim layer in / out point to playhead
B / N	Set work-area start / end to playhead
J / K	Previous / next keyframe in the current Keys/Graph Node/Layer/Comp scope (no wrapping)
Shift K	Toggle auto-key
+ / -	Zoom in / out (or scroll wheel)
H / L / S / B	Keyframe interp (Hold/Linear/Smooth/Bezier) — Keys/Graph with keys selected
1 / 2 / 3	Handle mode (Auto/Clamped/Free)
Delete / Backspace	Delete selected keyframes (or active layer)

Parenting finished layers

The layer-row Parent dropdown follows another layer's position, rotation and scale, not opacity. New parenting inserts a clean Parent Transform just before Output; it never moves your existing animated transforms before/after Draw nodes. Reparenting and No Parent preserve the target's current-frame placement. This final-image transform may soften vector/text when enlarged. See Group Transform & Layer Parenting for chains, legacy rigs and placement limits.