Why You Need the File, Not the Link
It's tempting to assume a clipping tool can just pull a video straight from its YouTube URL, but many tools, including ones built around direct file upload, don't support link ingestion. That's a deliberate scope decision in some tools rather than an oversight, and it means the workflow starts one step earlier than expected: getting the actual video file, not just its public link.
This is a minor extra step for anyone repurposing their own channel's content, since the file is either already saved somewhere or easily retrievable, but it's worth knowing before assuming a link will work.
Getting the Original File Back From YouTube Studio
A channel owner can download any of their own uploaded videos directly from YouTube Studio: open the video's details page and use the download option to save the original file. This works even for videos uploaded years ago, as long as the channel still owns them, and it produces the same file that was originally uploaded, ready to feed into a clipping tool.
Which Old Videos Are Worth Repurposing First
Not every old video is equally worth repurposing. Videos that performed well originally are a reasonable starting point, since they already proved the topic or format resonated with an audience, even if that audience was on a different platform at the time. Videos with a clear narrative arc, a story, an explanation, a strong opinion, tend to repurpose better than videos that were mostly visual demonstration with little spoken structure, since clip selection depends on what's said as much as what's shown.
What Changes When the Video Is Already Edited
Older YouTube videos are usually already edited, not raw footage, which changes what a clipping tool is working with. Instead of finding moments in an unstructured recording, it's finding moments within a video that already has its own pacing, music, and cuts. This generally works fine, a structure-based tool still looks for hook, re-hook, and resolution beats within the edited video, but background music or overlaid graphics from the original edit can sometimes carry into the new short in ways that are worth reviewing afterward.
ChatClip and Back-Catalog YouTube Videos
ChatClip accepts finished, edited videos as direct input, so an already-edited YouTube upload works the same way a raw file would. At launch, input is file upload only, there's no YouTube or other link ingestion, so the original video file needs to be downloaded from YouTube Studio (or pulled from local storage, if still available) before uploading.