Cloudflare opens Quicksilver to developers as Workers KV Instant
Quicksilver has sat underneath almost every Cloudflare request since 2020 without ever being on sale. Workers KV Instant turns it into a customer-facing key-value store with sub-two-millisecond reads and no TTL to wait for.
Cloudflare is putting its internal database on the price list. In a post published on 1 October, the company introduced Workers KV Instant, a new mode for Workers KV that is powered by Quicksilver, the key-value store Cloudflare has used for global replication since 2020 and has never previously offered to customers.
The numbers Cloudflare is quoting
KV Instant resolves reads in under two milliseconds at the 99th percentile, with p95 reads measured in microseconds. Cloudflare claims that is more than 100 times faster than classic Workers KV, where cached p99 reads sit at 160 milliseconds and 287 milliseconds across all reads. Writes replicate to more than 300 edge locations roughly 20 times faster, with a median of 107 milliseconds, a p95 of 181 milliseconds and a p99 of 256 milliseconds, against a classic mode the post describes only as under a second with a 4.38-second p99. The mode also drops the wait for a time-to-live to expire: Cloudflare says an update is globally available as soon as it is written.
The same API, with three differences
KV Instant keeps the Workers KV API, so get, put, list and delete behave the way developers already expect, and Cloudflare pitches it at the data that sits in the hot path of an application: feature flags, launch switches and configuration. Three things change. A namespace has to be created in instant mode. Metadata is unsupported, so getWithMetadata always returns null. And list operations return every matching key in a namespace, with no pagination. Cloudflare does not pretend the mode suits every workload, and classic Workers KV remains the option for data that does not need instant global reads.
Why Quicksilver stayed internal
Workers KV launched during Cloudflare's Birthday Week in 2018, and Quicksilver arrived two years later; the company says customers have asked for access to it ever since. The launch argument is consistency of experience as much as speed, since the same store already backs the requests Cloudflare serves on its own behalf, and the same replication path keeps the configuration that Cloudflare's own products read on every edge request.
Our opinion
The headline is latency, but the feature that matters is invalidation. A hundred-fold improvement on a read that already came back in under a fifth of a second is close to irrelevant next to the seconds teams lose waiting for a cache to expire, and that is the number Cloudflare should be selling. The trade-offs deserve a second read: dropping metadata and pagination turns a general-purpose store into a deliberately narrow one. That is the same bargain every edge platform asks for, and for feature flags it is a good trade, because the value of the flag is that it flips everywhere at once rather than that it is consistent in any deeper sense. Anyone porting a session store onto KV Instant and then wondering where the metadata went has misread the product.