NotesIQ

NotesIQ is a Chrome extension for Substack writers who want to understand how their Substack Notes perform. It reads your Notes through your existing Substack session and shows them in a dashboard ranked by engagement, with likes, restacks, comments and content type tracked for each Note. A Viral Alert flags a Note that takes off compared with your own baseline, and the tool keeps a longer history than Substack's own dashboard, which the site says shows only the last 90 days.

The extension also helps with timing and posting. A 7-day by 6-time-slot Best Time heatmap is built from your own posting history, alongside your current posting streak. You can compose a single Note or load a week of Notes into a queue, and NotesIQ uses Substack's own scheduler to publish them at the times you set. A Media Kit feature turns your subscriber count, top Notes and engagement into a one-page sponsor summary that can be exported from the panel.

NotesIQ is aimed at Substack creators who post Notes regularly and want to decide what to write and when based on their own numbers. The site says your Notes, profile and subscriber stats stay in your browser's storage, with no NotesIQ server receiving them, and that the product is a one-time $4.99 lifetime purchase with no subscription.