Confirm that the files are alternate versions
Two files can represent alternate editions of one film, consecutive parts of one film, or different films with similar names. Decide which relationship is true before changing filenames. Jellyfin has different naming conventions for versions and parts, so a label chosen only to make the screen look tidy can produce the wrong behavior.
For this task, use two files that genuinely belong to the same movie and keep a backup of their original names. Record which edition each file contains by inspecting your own records or the media. A resolution label is not proof of the actual picture resolution, and a name such as Director Cut should describe the real file rather than a hoped-for feature.
Match the folder prefix character for character
Jellyfin’s movie documentation says each version filename must begin with the complete parent-folder name, including any year and metadata-provider identifier. The version label follows that prefix using a supported separator. A difference in the base prefix can make the server treat the files as separate items instead of versions.
Compare the names as text, paying attention to punctuation, spaces and the identifier. For an original example folder named Private Film (2024), use that same base before each deliberate edition label. Preserve the real container extension. Renaming an extension does not convert the contents and can create a second problem unrelated to library grouping.
Inspect grouping before assessing playback
After the controlled naming change, refresh the relevant library item through your normal server route. Inspect whether there is one movie entry with the expected version choices. That is the grouping checkpoint. Then choose each version deliberately and confirm which file opens; a tidy library entry does not establish that both media files are playable.
Jellyfin documents ordering rules for the version list, including special handling for resolution-style labels. Do not rely on a casual assumption that the last-added file will become the default. Read the visible choice before playback, especially where editions have different running times or languages. Keep version labels understandable to other users of the library.
Questions answered
Can a small difference in the base name prevent version grouping?
Yes. Jellyfin requires the movie version’s filename prefix to match the parent folder exactly, including year and provider IDs when present.
Are two halves of a film alternate versions?
No. Consecutive parts and alternate editions are different relationships with different naming conventions. Identify the real relationship before renaming.
Sources & further reading
Official references for the subjects discussed. Service terms and device software can change.