Junk files
Also known as: junk data, clean junk files, residual files
Junk files are leftover data that no longer serves a purpose — app caches, temporary files, logs, crash reports, and remnants of deleted apps. Clearing them frees space safely because nothing you actively use depends on them.
- Leftover caches, temp files, logs, and app remnants
- Accumulates invisibly as you use a device
- Safe to clear — your real content is untouched
What counts as junk
Junk is an umbrella term for clutter a device accumulates as you use it: app caches, temporary files an app forgot to clean up, logs, crash reports, partial downloads, and leftovers from apps you already deleted. None of it is content you created or chose to keep.
It builds up invisibly. A device that has run for a year or two can hold several gigabytes of junk without you ever saving a single junk file on purpose.
Is it safe to clear?
Generally yes — junk is, by definition, data nothing important depends on, so removing it frees space without touching your photos, messages, or accounts. The one caution is wording: some "junk cleaner" apps overpromise, and on iOS there is no system-wide junk button, so the real wins come from clearing caches and removing duplicate or temporary files.