Cloudflare Workers KV Explorer

Cloudflare Workers KV is a globally distributed key-value store accessible from Cloudflare Workers. Values are replicated across Cloudflare's 300+ PoPs and served with low latency reads (~5ms median). KV supports string, JSON, ArrayBuffer, and ReadableStream values, with optional metadata and TTL. It uses eventual consistency — writes propagate globally within ~60 seconds, so it's ideal for read-heavy workloads like config, feature flags, and user session data.

Key limits: max 512 bytes. Value limits: max 25MB. Metadata: max 1024 bytes. TTL minimum: 60 seconds. List returns up to 1000 keys per call with cursor-based pagination. The free tier provides 100K reads/day and 1K writes/day. Paid plans offer higher limits. KV is not suitable for workloads requiring strong consistency, real-time updates, or heavy write throughput — use Cloudflare D1 (SQL) or Durable Objects for those.

expirationTtl specifies seconds from now until the key expires (relative). expiration specifies an absolute Unix timestamp (seconds since epoch). For example, expirationTtl: 3600 means the key expires in 1 hour. expiration: 1735689600 means the key expires at that specific Unix timestamp. The minimum value for either is 60 seconds. Keys that have expired are immediately unavailable but may not be purged from storage instantly.

First create the namespace: 'wrangler kv:namespace create MY_NAMESPACE'. This returns a namespace ID. Add it to wrangler.toml: [[kv_namespaces]] binding = "MY_KV" id = "<namespace-id>". For local dev/preview, create a separate preview namespace: 'wrangler kv:namespace create MY_NAMESPACE --preview' and add the preview_id. In your Worker code, access it as env.MY_KV which has the full KVNamespace TypeScript interface.

KV reads are already fast (~5-50ms globally) but you can layer the Cache API on top for sub-millisecond repeated reads within the same PoP (cache.match / cache.put). For stale-while-revalidate, use ctx.waitUntil() to update KV asynchronously after returning the cached response. For TTL-based invalidation, put values with expirationTtl so they auto-expire. For strong invalidation, include a version in the key (e.g., 'config:v3:settings') and update atomically.