# Cloudflare opens Quicksilver-backed KV Instant — fast global reads with $100-per-MB storage

Cloudflare's October 1 private beta brings its internal Quicksilver key-value system to Workers KV namespaces. Its vendor-measured sub-2ms p99 reads and fast global propagation are attractive for tiny configuration datasets, but storage and writes cost dramatically more than classic KV.

Workers KV Instant is built for hot-path flags, not general storage: Cloudflare quotes 1.62ms p99 reads, $0.20 per million reads, $0.10 per write and $100 per MB each month. Private beta limits are strict.

- Status: Active
- Published: 2026-10-11T09:00:36+13:00
- Updated: 2026-10-11T09:00:36+13:00
- Categories: Cloud & Infrastructure, Edge & CDN, Databases & Storage
- Tags: Cloudflare, edge storage, pricing, Quicksilver, Workers KV
- Canonical HTML: https://beyondthe.news/dossiers/cloudflare-workers-kv-instant-quicksilver-beta-pricing-limits

## What changed

On October 1, 2026, Cloudflare introduced Workers KV Instant in private beta. New namespaces can use the Quicksilver-backed 'instant' mode through most existing Workers KV API calls. Cloudflare reports 1.62ms p99 read latency and approximately 256ms p99 replication to its edge locations, compared with 287ms p99 overall reads and 4.38s p99 write replication in its comparison for classic KV. These are Cloudflare's measurements, not independent production benchmarks.

## Why it matters

Feature flags, small configuration maps and routing switches can be read on every request with lower latency and faster worldwide update propagation. But KV Instant is economically and operationally unsuitable for ordinary caches, large records or frequently updated data. Its low read price hides unusually high write and storage charges, creating a concrete architecture and billing decision for edge developers.

## The speed comes from a different replication system

Classic Workers KV relies on a different read/replication architecture. Instant mode uses Quicksilver, which Cloudflare has long used for internal edge configuration. The headline 100-times-faster claim compares vendor-measured p99 timings; it should not be interpreted as a general 100x application-speed improvement.

## The pricing reverses the usual KV tradeoff

For a small namespace read millions of times and rarely changed, the lower per-read cost can make sense. But one thousand write/delete/list operations cost $100, before storage and reads, and a full 1MB stored for a month has a nominal $100 storage charge. Engineers should calculate real write rates, retained bytes and namespace count before opting in.

## Compatible API does not mean drop-in semantics

Namespaces must be created in instant mode, metadata support is absent, list pagination is absent and writes are limited to one per namespace per second. Code relying on getWithMetadata, paged key listing or frequent configuration updates needs changes or should remain on classic Workers KV.

## Key details

- Private beta announced October 1, 2026; requires access and a namespace created with mode 'instant'.
- Cloudflare reports 1.62ms p99 reads and 256ms p99 write replication; real workloads may differ.
- Read/get (Class B): $0.20 per million requested keys versus $0.50 per million for classic KV.
- Put/delete/list (Class A): $0.10 per operation, not per million.
- Storage: $100 per MB per month versus $0.50 per GB per month for classic KV.
- Maximum one megabyte of data per namespace, up to 10,000 key-value pairs, 300-byte maximum key length.
- One write per namespace per second; classic KV instead limits writes per key.
- KV Instant does not support metadata; getWithMetadata returns null. list returns all matching keys with no pagination.

## Builder takeaways

- Use Instant only for very small, globally read-heavy settings or feature flags with infrequent writes.
- Estimate cost using $0.10 per Class A operation and $100 per MB-month, not only cheaper reads.
- Audit metadata and pagination dependencies before adapting existing KV code.
- Test real tail latency and update propagation during private beta; the published figures are vendor benchmarks.
- Retain classic KV for general-purpose storage and high-update workloads.

## What to watch

- General availability and any changes to pricing, quotas or write-frequency limits.
- Independent latency/consistency measurements for configuration workloads.
- Whether Cloudflare adds metadata or alternative list semantics.

## Uncertainties

- Private beta access and product behavior may change before general availability.
- The published latency figures are Cloudflare benchmarks; independent measurements across representative workloads are limited.
- Current pricing and caps may be revised before broader rollout.

## Sources

- [Introducing Workers KV Instant — powered by Quicksilver](https://blog.cloudflare.com/workers-kv-instant/) — Cloudflare Blog · primary announcement and pricing · 2026-10-01T00:00:00+13:00. Vendor latency table, beta status, API differences, per-operation and storage pricing, caps.
- [Cloudflare launches Workers KV Instant, a Quicksilver-backed mode](https://www.brocker.org/cloudflare-workers-kv-instant-quicksilver) — Brocker.org · independent technical coverage · 2026-10-01T00:00:00+13:00. Independent restatement of product scope and constraints; does not independently benchmark latency.