A clicking extruder is one of the most diagnostic sounds in 3D printing
Under-extrusion, gaps between extruded lines, weak or missing walls, a generally starved look, has several plausible causes, but one symptom cuts through most of the ambiguity fast: a clicking or skipping sound from the extruder almost always means the extruder cannot feed filament as fast as the print is asking for it, whether from insufficient grip, a partial blockage, or too high a speed demand. This tool weighs that symptom heavily when present, and falls back to other hypotheses when it is not.
How the triage works
A reported clicking sound strongly favors the feed hypothesis (idler tension, a worn gear). Onset from the very start favors temperature and feed together; onset developing mid-print favors a developing partial blockage instead. A recent filament change raises filament condition (diameter variance, moisture); worse performance specifically in fast or fine-detail regions raises the speed-demand hypothesis, since some hotends simply cannot melt filament fast enough at high flow rates.
Worked example
Under-extrusion from the start, clicking sounds heard, no recent filament change, worse in fast regions: the tool ranks extruder feed as the top hypothesis given the clicking sound, with speed demand as a real secondary factor given the fast-region pattern, recommending a feed-mechanism check first before assuming a speed-related hotend limitation.
A common mistake
A frequent error is repeatedly attempting a cold pull on a nozzle that actually needs replacement, wasting time on a fix that was never going to work. If a suspected blockage survives two careful cleaning attempts without improvement, treat that as a signal to swap the nozzle rather than a reason to try the same cleaning process a third or fourth time.
Limitations
This tool ranks plausible causes from the symptoms you described. It cannot see your printer, so treat the ranked list as a place to start testing, not a confirmed root cause. If a suspected blockage does not clear after one or two cleaning attempts, treat that as a stop condition and consider nozzle replacement rather than repeating the same fix indefinitely.