The plain-English version
A traversal boundary that selects keys strictly beyond a recorded key rather than including that key again.
Why it matters
It helps avoid repeating a boundary item when resuming a stable, uniquely ordered collection.
Let’s make it click
An IndexedDB range can request keys greater than the saved key using an open lower bound.
Vibe Bro’s heads-up
Excluding a key does not freeze concurrent data or make a nonunique sort field sufficient. Preserve the complete ordering and traversal contract.
You might also hear
- open lower bound
- exclusive pagination boundary
- strict cursor range
Vibe Bro’s field notes
Use the datastore's documented comparison rules, direction, and key representation.
The docs behind it
Research sources reviewed .
Editorial review · October 28, 2026
Supported: MDN confirms IDBKeyRange.lowerBound(key, true) excludes the key; stable unique ordering and concurrency caveats are correct.