OneX Inbox is email engineered like a race engine. We profile every interaction, budget every frame, and refuse to ship anything slower than instant. The result is the fastest email client ever measured.
Team — this week's numbers are in. 99% of message opens now complete in under 40 milliseconds, cold cache included.
For reference: a single eye blink takes about 100ms. We are officially rendering email faster than the human eye can close.
Next target: shaving another 6ms off first paint. It's never fast enough. — P
We run the same suite against every major client, every week: time from click to a fully rendered message, cold cache, real network, identical hardware.
Median of 1,000 trials per client · February 2026 internal benchmark suite
No single trick — an architecture where every layer is built for speed and measured in production.
Every message is stored and indexed locally. Reads never touch the network, so the speed of light is the only latency left.
OneX models what you'll open next and pre-renders it in the background. By the time you click, the work is already done.
Each interaction has a hard frame budget enforced in CI. If a change misses the budget, it doesn't ship. Ever.
OneX Inbox exists because we believe the tool you use a hundred times a day should cost you zero seconds of waiting. Now it does.