Quick answer: open the Edit page, choose View > Show Duplicate Frames, then scan the timeline for colored bars along the top of your clips. Matching colors mark timeline ranges that use the same source frames more than once. Zoom out to find the pairs, then zoom in before you touch anything. A duplicate marker can expose an accidental repeated shot, but it can just as easily sit on an intentional cutaway, replay, flashback, split-screen layer or copied background.
The tool answers one narrow question: where does this timeline reuse the same part of a source clip? It doesn't prove the edit is wrong, and it can't see repeated images that are already baked into a single media file.
Turn On Show Duplicate Frames
- Open the timeline on the Edit page.
- Open the View menu.
- Enable Show Duplicate Frames.
- Zoom out until you can see a useful span of the timeline.
- Look for short colored bars along the top edge of the video clips.
Resolve draws the markers right on the clips; there's no separate report window. The 21.1 Reference Manual calls the feature Duplicate Frame Detection, or Dupe Detection, and describes exactly that: colored bars at the top of clips wherever a range of frames is used more than once. On a dense timeline, start wide enough to spot repeated color pairs, then zoom toward one pair. Bigger video tracks help too, because the bars live on that top edge.
What the Colored Duplicate-Frame Bars Mean
A colored bar marks the part of a clip whose source frames show up somewhere else in the same timeline. Another bar in the same color points you to the matching use. The color is there to connect the occurrences. It isn't a warning level, and it won't tell you which copy is the mistake.
| Marker pattern | Likely meaning | Next check |
|---|---|---|
| Two full-width bars on identical short clips | The complete source range was used twice | Confirm whether the second use is intentional |
| A short bar on part of each clip | Only an overlapping source-frame range is repeated | Compare source In and Out points |
| Several bars with the same color | The same source section appears in several places | Review the edit purpose of every occurrence |
| No marker, but playback repeats visually | The repeated images may be inside one source file or caused by cadence | Inspect the source and frame-rate path |
Watch for partial bars. Two clips can have different durations, sit in different places and show different content at their ends, yet still share a handful of source frames in the middle. That happens all the time after you trim alternate versions of the same shot.
Scan a Long Timeline Without Losing Context
- Save the current timeline state, or make a named duplicate of the timeline, before you make broad changes.
- Disable unrelated overlays if the clip area is visually crowded.
- Zoom out and scan from the first video track downward, one section at a time.
- When a color shows up, find every bar that matches it before you judge the first one.
- Zoom in and inspect the exact beginning and end of the marked range.
- Play several seconds before and after each occurrence with audio.
- Record the timeline timecodes if the review is being handed to another editor.
The second occurrence isn't automatically the wrong one. The early use might be a teaser that spoils a later reveal, or the later use might be the leftover. Judge the pair in story order, and listen as well as look: duplicated dialogue, room tone, a music hit or an ambient sound can give the reuse away even when the picture is subtle.
Decide Whether the Reuse Is Intentional
Duplicate-frame detection is a QC aid, not an automatic delete list. Keep a repeated range when it serves the edit and the viewer is meant to recognize or accept it.
- Usually intentional: replay, recap, flashback, picture-in-picture, split screen, before-and-after comparison, freeze-frame design, looping background, or a deliberate reaction callback.
- Needs review: generic B-roll, an interview cutaway, establishing footage, or a montage shot that may feel familiar without being obviously repeated.
- Often accidental: two adjacent copies, a paste left under another track, repeated dialogue, or the same insert used twice within a short sequence without a narrative reason.
If you built the repetition on purpose, the duplicate clip guide walks through copy-and-paste and modifier-drag methods. The marker is still handy then, because it confirms exactly which source range you reused.
Remove or Replace an Accidental Duplicate Safely
Don't delete the marked clip until you've checked what holds the timeline together around it. A plain delete leaves a gap, a ripple delete pulls every later edit earlier, and replacing only the video can knock linked audio out of sync.
- Select the occurrence you intend to change and confirm its track, linked audio, transitions, keyframes, and connected titles.
- Pick a replacement shot that does the same editorial job, or trim a different unused range from the original source.
- Use Replace Edit, overwrite, or a controlled trim when the sequence duration must stay fixed.
- Use ripple removal only when the sequence should become shorter.
- Replay the surrounding edit, then check whether the duplicate marker is gone or has just moved to a different overlap.
A new trim from the same source clip can still overlap the original occurrence. Push the source In point past the marked range, or choose another shot. When the repeat is only a few frames long, one trim may fix it; when the whole clip is marked, a real replacement is usually the cleaner answer.
Why Duplicate-Frame Markers May Not Appear
Show Duplicate Frames is not enabled
Go back to the View menu and make sure the option is checked. It's easy to miss after switching workspaces or opening another timeline.
The timeline is too compressed or the tracks are too small
Increase the track height and zoom into the area you suspect. A very short repeated range is hard to spot at a wide timeline scale.
The clips look similar but use different source frames
Two shots can come from the same camera take and still use neighboring, non-overlapping ranges. Looking alike isn't enough; the detector only cares about repeated source frames.
The repeat is inside a compound clip or nested timeline
The open timeline may treat a compound clip or nested timeline as a single clip. Open the underlying timeline or compound clip and check it where the repeated source media is actually cut. The compound clips guide shows how to step inside that structure and decompose it.
The same recording exists as two separate media files
Duplicate detection follows source usage. Two separately imported or transcoded files can hold identical pictures and still count as different media items. Use filenames, reel or camera metadata, timecode and a side-by-side look to catch those.
Timeline Duplicates Are Not Repeated Frames Inside a Source File
A clip can stutter because the file already contains repeated frames, because a frame-rate conversion created them, or because playback can't decode the media in real time. Show Duplicate Frames isn't built to diagnose any of that. It looks for the same source range used in more than one place on the timeline.
If one continuous clip shows repeated motion but has no colored duplicate pair, look at the source and the frame-rate path. The frame-rate guide covers project, timeline and source FPS decisions. If the frames are unique but playback still hesitates, the slow playback guide helps you separate decoding performance from editorial repetition.
Check Audio Even Though the Overlay Is Visual
The marker points to reused video frames, but the editorial problem is often easier to hear than see. A duplicated breath, word, footstep, music hit or room-tone pattern can give away a copied section that slips past a quick visual scan.
- Listen through both occurrences at normal speed.
- Check linked audio and separately edited audio tracks.
- Inspect transitions that may hide the picture cut but repeat a sound.
- Confirm a replacement did not leave the old audio beneath it.
When the video reuse is intentional but the repeated sound is distracting, replace or extend the audio on its own. Keep sync wherever dialogue or visible action needs it.
Run a Final Duplicate-Frame Check Before Export
Turn the overlay on for the final timeline, not just the assembly or rough cut. Scan the whole program after relinking, reconforming, copying scenes between timelines or rebuilding a sequence from XML. Those are exactly the moments when an old clip survives under its replacement or a section gets pasted twice.
- Scan every visible video track for matching bars.
- Mark each pair as intentional, acceptable or accidental.
- Check nested timelines and compound clips separately when they contain editorial content.
- Render a short proof around every corrected section.
- Export the final range and watch the rendered file instead of assuming the timeline state carried through.
The export guide covers render range and post-render checks. Duplicate markers never appear in the delivered video; they're an editor-side overlay. So your last check has to be the rendered picture and sound.
Duplicate Frames FAQ
Do the colored duplicate-frame bars appear in the export?
No. They're timeline overlays for editing and review, not part of the picture.
What does the same marker color mean?
It links occurrences that share the same source-frame range. Treat the color as a pairing aid, not a severity rating.
Why are two clips from the same file not marked as duplicates?
They may use different, non-overlapping frame ranges from that file. The detector marks reused frames, not every reuse of the same media item.
Which duplicate should I delete?
Neither, by default. Watch both in story order, work out which use is intentional, and change the one that hurts continuity, timing or clarity.
