How to export your data
In Google Search Console, open Performance → Search results, pick a date range (the last 3 months is a good start), and click Export → Download CSV. You get a ZIP with Queries.csv, Pages.csv and a few other files. Upload the ZIP as it is, or just Queries.csv or Pages.csv.
Want to see what changed? Use Compare in the date picker before exporting (for example, last 3 months vs the previous period). The analyzer then also lists what gained and lost clicks.
What it finds
Almost on top: search terms and pages at positions 4 to 20 with real demand, sorted by how many extra clicks a top-3 position would bring. These are usually the fastest wins.
Ranking well, but few clicks: page-one results whose click rate is far below normal for their position. The fix is usually a better title and description.
Biggest drops and gains, when you upload a comparison export. You can download every opportunity as a CSV.
Private by design
The file is read in your browser and never uploaded to Clarnic or anywhere else. Close the tab and it's gone.