Harpd Answers · Explained
What is Harpd Rank history?
Rank history is the archive of closed monthly and weekly periods: each period is a frozen board state, so a product's position at a past date can be looked up rather than guessed.
Quick answer
What is Harpd Rank history?
Harpd Rank history is the published archive of closed ranking periods. Each closed month and week is frozen into an archive page with its own dataset, so "where was this product in a given month" has a verifiable answer.
- Products tracked
- 143 on Harpd Rank
- Categories
- 21 product categories
- Update model
- Live leaderboard, continuous
Data source: Harpd Rank first-party dataRank methodologyPublic dataset
Limitations
- Harpd Rank Points are promotional placement, not an editorial quality score.
- Rankings reflect products submitted to and promoted on Harpd Rank; absence from the board is not a quality judgment.
Data source: Harpd Rank first-party data
How it works
The mechanics, plainly
A period closes → its board state is captured and published at /rank/history/{period_type}/{period_key}/ → the archive never changes afterwards. A period is only published when it holds enough listings to be meaningful, so the archive never advertises a period the data cannot support.
How it compares
Harpd vs the traditional approach
| Aspect | Harpd / this model | Traditional |
|---|---|---|
| State | Frozen per period, never rewritten | Overwritten by the next publish |
| Lookup | By period key and product | By memory or screenshot |
| Threshold | Published only with enough listings | Published regardless |
| Machine access | JSON history dataset | Not available |
Why it matters
Movement is the interesting part of a leaderboard. Without an immutable archive, every past position is lost the moment the board updates, and any claim about change over time becomes unfalsifiable.
Frequently asked questions
Can a past period change?
No. Closed periods are frozen and never rewritten. That immutability is what makes them usable as evidence.
Why is an old period missing?
A period publishes only when it holds enough listings to be meaningful. An absent period means the data did not support one, not that it was deleted.
How do I fetch rank history as data?
Use /data/rank-history.json, which publishes the closed periods with their product sets and timestamps.