About tracking sleep quality by hand
Wearables and phone apps can estimate sleep stages, but a short subjective journal captures something they can't: how you actually felt about the night, plus the everyday choices around it. Sleep researchers have long used simple 1-to-5 quality ratings alongside sleep diaries because subjective quality doesn't always track cleanly with hours logged — someone can sleep eight hours and still feel rough, or sleep six and feel fine, depending on timing, stress and habits earlier in the day. This journal keeps the entry short on purpose: a date, an hours figure, a quality tap, five habit checkboxes and an optional note, all of which take under a minute once it's part of your routine. The 14-day bar chart exists because two weeks is usually enough to separate a one-off rough night from an actual dip worth addressing, without so much history that the chart becomes unreadable. The pattern detector looks specifically at your worst nights, rated 1 or 2, and tallies which checked factors show up most often among them, which is a simple but genuinely useful way to surface a habit you might not have connected to your sleep otherwise, like a pattern of afternoon coffee or late scrolling. Everything is stored only in your browser's local storage, one entry per calendar date, so re-logging a date cleanly overwrites it instead of piling up duplicates.
Subjective still matters
How rested you feel is real data, even without a wearable to back it up.
Two weeks is enough
A 14-day window balances catching a trend against keeping the chart readable.
Private by default
Your journal lives in local storage on your device, not on a server.