Cloudflare launches Workers KV Instant for sub-2ms reads

Cloudflare has rolled out a new mode for its Workers KV service that promises to eliminate cold-read latency and accelerate global data propagation. Workers KV Instant, now in private beta, is built on the company’s internal Quicksilver key-value store, which already handles nearly every request across Cloudflare’s network. The offering is positioned for read-heavy, low-write workloads such as feature flags, user preferences, and application configuration that require near-instant global availability after updates.

How it works

Workers KV Instant retains the existing Workers KV API—methods like get(), put(), list(), and delete()—but replaces the underlying storage engine with Quicksilver. This change delivers a 100-fold improvement in read performance at the 99th percentile, with p99 reads resolving in under 2 ms and p95 reads measured in microseconds. Writes replicate globally in approximately 250 ms for 99% of updates, a 20-fold speedup over the classic mode. The service is designed for small datasets: namespaces are capped at 1 MB and 10,000 key-value pairs, with individual keys limited to 300 bytes.

Pricing and trade-offs

KV Instant is priced to favor read-heavy workloads. Class B operations (reads) cost $0.20 per million, a 60% reduction from the classic mode’s $0.50 per million. However, storage and Class A operations (writes, deletes, lists) are significantly more expensive: $100 per MB per month for storage, compared to $0.50 per GB in classic mode, and $0.10 per Class A operation, up from $5.00 per million. The service also enforces a rate limit of one write per namespace per second to maintain consistency.

Who it’s for

The service targets developers who need to read configuration data on the hot path of every request, such as feature flags, A/B test settings, or regional routing rules. Cloudflare’s own use cases—including dynamic homepage updates during product launches—are cited as examples. KV Instant is not suitable for large datasets or high-write workloads, where the classic mode remains the better fit. The private beta is open for sign-ups, with plans to expand access in the coming months.