Most video projects live in Premiere. But the moment you need motion graphics, compositing, or anything beyond what Premiere's built-in tools can handle, After Effects enters the picture. And with it comes a dependency chain that makes media cleanup genuinely dangerous if you do not understand how the two applications are connected.

How Dynamic Link Works

Adobe Dynamic Link lets you place an After Effects composition directly on a Premiere timeline without rendering it first. The Premiere sequence references the .aep file, and whenever Premiere needs to display that section of the timeline, it asks After Effects to render the comp in real time. This is powerful — you can adjust a title design in After Effects and see the change reflected in Premiere without any intermediate export step.

But Dynamic Link creates a hidden web of dependencies. The Premiere project references the .aep file. The .aep file references its own set of media: footage layers, image sequences, audio files, illustrator documents, fonts, expressions that point to external data files. If any of those files are moved or deleted, the After Effects comp breaks, and so does the Premiere timeline that depends on it.

This means that when you are cleaning up media for a Premiere project, you cannot only think about what Premiere is using. You also have to think about what After Effects is using, because those files are indirectly required by Premiere through the Dynamic Link chain.

Why Manual Cleanup Breaks Things

Here is the scenario that burns editors. You finish a project and look at the media folder. There is a texture file — maybe a film grain overlay or a paper texture — that you do not recognize on any Premiere timeline. It seems safe to delete. But that texture is used in an After Effects comp that is on your Premiere timeline, buried inside a lower third or a transition. Delete the texture and the AE comp renders incorrectly. You might not even notice until someone plays back that section of the timeline months later.

The same problem applies to footage. An After Effects comp might use a piece of footage as a background plate or a matte that you never placed directly on the Premiere timeline. As far as Premiere is concerned, that footage is not in any sequence. But it is critical to the AE comp that is.

This is why experienced editors tend to follow a "delete nothing" policy when AE is involved. The risk of breaking a linked comp is too high, and the time required to manually trace every dependency is impractical. So the unused media stays, and the project keeps growing.

How Clip Sweeper Handles AE Projects

Clip Sweeper takes a different approach. Rather than only looking at Premiere project files, it can also parse .aep files to understand what media After Effects is using. When you point Clip Sweeper at a folder containing both .prproj and .aep files, it builds a unified dependency map across both applications.

The logic works like this: Clip Sweeper reads every sequence in every Premiere project to find directly used media. It also identifies any Dynamic Link references to After Effects compositions. For each referenced .aep file, it parses the After Effects project to find the media files used in those compositions. All of those files — whether they appear on a Premiere timeline directly or are used inside a linked AE comp — are marked as used.

The safety model is deliberately conservative: if a file appears in any project — Premiere or After Effects — it is marked as used. A media file is only flagged as unused if it does not appear in any sequence across any Premiere project and does not appear in any After Effects composition that is referenced by those Premiere projects.

The Edge Cases

Real-world projects have complicating factors. Some editors use After Effects compositions that are not linked via Dynamic Link but are instead rendered and imported as standalone video files. In that case, the rendered file appears on the Premiere timeline, but the source AE comp and its media are a separate concern. Clip Sweeper handles this by treating the rendered file as used media in Premiere while also scanning the AE project independently.

Another common pattern is having multiple AE projects associated with a single Premiere project — one for titles, one for VFX, one for social media graphics. Clip Sweeper will scan all of them as long as they are in the analysis scope, building the full cross-reference map regardless of how many project files are involved.

There are also cases where AE comps reference other AE comps through precomps, creating deeply nested dependency chains. A texture used in a precomp that is nested inside another precomp that is placed on a Premiere timeline is still a required file. The parser follows these chains to their end points.

A Practical Workflow for Multi-App Projects

If you work with both After Effects and Premiere regularly, here is a workflow that keeps things safe:

  1. Keep AE and Premiere project files in the same parent directory. This makes it straightforward to scan everything at once and ensures no cross-references are missed.
  2. Finish all AE work before cleaning up. Do not attempt media cleanup while you are still iterating on motion graphics. Wait until all comps are final and approved.
  3. Scan all project files together. Point Clip Sweeper at the top-level project folder so it picks up every .prproj and .aep file. Scanning a subset risks missing dependencies.
  4. Review the results with comp names in mind. When Clip Sweeper shows you unused files, think about whether any of them might be associated with After Effects work. If a file is marked unused and you are confident it is not part of any AE pipeline, it is safe to remove.
  5. Keep the AE project files themselves. Even if you delete unused media, always keep the .aep and .prproj files. They are small and they are the record of your work. Archive them permanently.
The safest cleanup is the one that understands every link in the chain — Premiere sequences, Dynamic Link references, and After Effects compositions, all at once.

Working across After Effects and Premiere does not have to mean keeping every file forever. It just means your cleanup tool needs to be as aware of the connections between applications as you are. Anything less is guesswork, and guesswork is how projects break.