GitHub made the contribution graph iconic: a year of work in one glanceable grid, green squares for busy days. Gamers want the same thing — a calendar of *when* they played, not just how much in total. The catch is that Steam doesn't store per-day history anywhere, so building a real heatmap takes ongoing measurement.
Why Steam can't show this natively
The Steam Web API exposes exactly two playtime figures per game: a lifetime total (`playtime_forever`) and a rolling two-week figure (`playtime_2weeks`). There is no endpoint for “hours played on March 4th,” and Valve keeps no public history. Once a day passes without being measured, it's gone forever.
How snapshot heatmaps work
The trick is subtraction. Take a snapshot of every game's lifetime totals today, another tomorrow, and the difference is that day's playtime — per game, down to the minute. Repeat daily and the diffs accumulate into a genuine history: streaks, marathon weekends, dry spells, release-day spikes.
That's the engine behind MySteamStats. Paste your profile and a tracker starts snapshotting it automatically — daily on the free tier, every six hours for Pro subscribers. Your heatmap fills in from that day forward, one cell at a time.
- History can't be backfilled. Any service claiming otherwise is estimating. Real history starts when tracking starts.
- New trackers get a preview immediately: the first snapshot seeds a rough picture from your recent two-week activity.
Start your calendar today
Look up your profile on the homepage and tracking begins automatically — no password, no sign-up form, just Steam OpenID when you choose to sign in. Every future session lands on your heatmap, and your longest streak gets counted.
Frequently asked questions
Can a heatmap show my past years?
No. Per-day data doesn't exist until something measures it. Services offering “historical” heatmaps are generating estimates from current totals, not real measurements.
Does tracking require access to my account?
No. Snapshots read the same public Web API data any visitor can see. Signing in with Steam just lets the site pin the tracker to you and unlock the dashboard.
What counts as an “active day”?
Any day whose snapshots show more playtime than the previous day's baseline — typically meaning you launched something and played it.
Put your own numbers on the board
Look up any public Steam profile for hours played, library value, inventory worth and a playtime heatmap — free, no sign-up.