Kdenlive 26.08 documentation · Primary-source explanation; examples are illustrative. Instructions are based on publisher guidance; a UK IPTV account was not tested on this platform.
Identify which kind of data occupies the space
Kdenlive 26.08 documentation separates project cache data, such as timeline previews, proxies and thumbnails, from external project assets. Inspect the relevant categories before choosing a delete control. Reclaiming preview space and removing unused source clips are different tasks, even when both appear near project management settings. Start from the storage problem you intend to solve rather than treating every item described as unused as disposable.
Review one project and category first
For an original cleanup plan, finish and save a permitted edit, then examine its cache breakdown. If timeline previews account for the space you no longer need, select that cache category and confirm the project identity. The documentation provides category cleanup controls and a link to the cache location. Keep the original recordings and an appropriate project backup available. Expect to review the editing experience afterwards rather than judging cleanup only by a smaller disk usage number.
Distinguish removal from the project and storage
The Project Files documentation explicitly states that Delete files removes unused files from the filesystem, while Remove Unused Media removes items from the project. A clip unused in this timeline may still be required for a later revision or another project. The broader cached data manager also has separate backup and proxy cleanup controls with age settings, so review their scope independently. Use the control which matches the intended operation and retain the resources needed to reopen and revise the work.