Editing is the act of placing marked source material onto the timeline and arranging it into a sequence. Lightworks gives you a small set of core operations - insert, replace, overwrite, delete, remove, and split - that you can drive from the viewer buttons, the keyboard, or directly on the timeline.
Most edits follow the same rhythm: choose your source, mark what you want, target the timeline track and position, and perform an edit. The marked source section lands on the targeted tracks at the playhead. This is the heart of three-point editing (see below).
Both sides use the same control: enable or disable tracks (V1, A1, and so on) on the source to choose which of its tracks take part in the edit, and on the sequence to choose where they land. The source's monitor buttons only affect what you see and hear - they don't change what gets edited in.
An insert edit pushes existing material aside and drops your clip in, lengthening the sequence. Everything after the insert point moves later in time. Use insert to add a shot without overwriting what's already there.
A replace (overwrite) edit lays your clip over whatever is at the playhead, keeping the sequence the same length. The new material replaces the old in place. Use replace to swap a shot, drop a cutaway onto a higher track, or lay sound under existing picture.
Tip: Insert changes the timing of everything downstream; replace does not. When sync matters, replace is usually the safer choice.
Three-point editing means you set three of the four possible in and out points, and Lightworks works out the fourth:
This is the precise, repeatable way to drop material to length - ideal for filling a gap or matching a music beat.
Load and mark a clip in the source viewer, target your tracks, then click Insert or Replace to edit it into the sequence shown in the sequence viewer. The playhead advances so you can build a cut clip by clip. This viewer-driven workflow is covered end to end in Quick start: create your first edit.
You don't have to go through the source viewer:
The core operations sit as buttons on the timeline toolbar, and work on the marked section:
| Operation | What it does |
|---|---|
| Insert | Adds material and ripples the rest of the sequence later |
| Replace | Overwrites material in place, keeping length |
| Remove | Removes the marked section and leaves a gap (black) |
| Delete | Removes the marked section and closes the gap |
| Split | Adds a cut at the playhead without removing anything |
Split is its own button, distinct from Delete, so cutting a clip in two is a separate, clear action. (Its underlying command is Empty cut - the classic Lightworks name for a cut with nothing removed.)
Insert follows Track Sync: with it on, the tracks sitting out the insert are padded with black at the edit point so they keep their alignment; with it off they stay where they are (see Trimming).
Delete closes exactly what you deleted, and every track moves by the same amount or not at all. Where another track has content at the same position there is nothing for it to give, so it stays put and the sequence keeps its length rather than that track being dragged out of step.
Lightworks also has a timeline clipboard, which is often the fastest way to rearrange material:
Paste lands on the tracks the material came from. Which tracks the clipboard holds was settled when you copied, so track targeting has no say at the other end. A paste that inserts follows Track Sync like any other insert: with it on, a track with nothing to receive is given black at the edit point so the whole timeline stays in step. Locking a track is the one thing that keeps it out.
Mark a section, cut it, park where it should go, and insert - a clean way to re-order scenes without dragging. If every track is disabled or locked, the clipboard commands say so rather than appearing to do nothing.
A gap is empty space on a track; on video it reads as black, on audio as silence. Gaps appear when you remove material, and when you deliberately want a hole in the picture or sound.
Right-click a gap and you get two choices, which do different jobs:
Note: Taking black out on one track alone makes that track shorter than the others, so anything after it on that track moves earlier. That is usually what you want when tightening a single audio track, but check the result if the track is carrying sync sound.
Delete Gaps in the Clean Up menu does the same job across a whole sequence or marked region (see Timeline tools and commands).
Every edit is undoable. Use undo to step back through your changes and redo to step forward again. Combined with Lightworks' continuous auto-save, you can experiment freely - there's no way to lose the project, and any edit can be reversed.