When your traffic drops, the first question should be "was there an algo update?" — not "what did I break?" This tool overlays your GSC Performance time-series against the Google algorithm-update calendar. Regressions that line up with a known update window get flagged. SEMrush Sensor is included in their $139/mo plan; this does the correlation for free.
Read the story behind this tool: Check the update calendar before you blame your own work →
Export "Dates" breakdown from Search Console Performance report. Columns we need: Date, Clicks, Impressions. CTR and Position optional. Paste the raw CSV below.