Privacy

No storage of User-Agents with IPs. UAParse parses the string in memory and returns the result. It does not write User-Agent strings to any database, log or analytics tool, and never stores them next to an IP address.
Short-lived rate-limit counters. To enforce the free per-minute limit, Cloudflare's rate-limiting feature keeps a counter keyed by your IP address for about 60 seconds. It holds a number, not your User-Agent.
In-memory result cache. Parse results are cached in the Worker's memory, keyed by a SHA-256 hash of the User-Agent, so repeat lookups are fast. The cache holds no IP or API key, is never written to disk or storage, and disappears when the Worker instance is recycled.
API keys. Only a SHA-256 hash of each key is stored (Cloudflare Workers KV). Usage counters per key per UTC day are kept in a Cloudflare Durable Object for about two days. They contain counts only.
No logs, cookies or analytics. Cloudflare Workers Logs are turned off for this service, there are no cookies, and the page loads no third-party scripts.
Infrastructure. UAParse runs on Cloudflare Workers. Cloudflare processes requests as our infrastructure provider.