How is Superhuman so fast? A deep dive into the need for speed in email

Speed is the name of the game for Superhuman. This slick email app feels instantaneous – with none of the lag that haunts most software. Emails and searches flow by in a blink.

So how did they make an email client so fast you can barely perceive delay? Let‘s dig into the engineering tricks that enable lightning fast interactions under 100 milliseconds.

Perceiving Speed: Why Every Millisecond Matters

Superhuman isn‘t just fast. It‘s ridiculously fast – 3X faster than Gmail, in fact.

You might think 100 milliseconds of latency is negligible. But our perception of time makes even small differences noticeable.

Under 50ms starts feeling instant. Up to 100ms still feels snappy. But around 100-300ms, delays become perceptible. Beyond 500ms, you really notice the lag.

Superhuman engineered their app for 50ms or less latency on every action. For comparison, Gmail‘s latency is 150-400ms.

Those hundreds of milliseconds start to add up when you‘re powering through hundreds of emails. Even minor delays can disrupt your state of flow.

So while the naked eye can‘t perceive nanoseconds, your brain certainly can. This speed is not a novelty – it‘s essential for peak email efficiency.

Optimizing at the Millisecond Level

So how does Superhuman achieve such incredible speeds? Their custom-built web app is obsessed with optimization down to the millisecond. Some of the key techniques include:

Minimal Animations

Fancy animations may delight users, but they require time and computing power. Superhuman cuts out all extraneous animations that don‘t provide core value. For example, ajax loader animations are replaced with simple text like "Loading…", eliminating 300+ms of delay.

Predictive Caching

Superhuman predicts what data you‘ll need and pre-caches it for instant access. This prevents wasted time fetching data when you open an email or search. The app also uses client-side caching to keep data available between sessions.

Keyboard Shortcuts

Keyboard shortcuts eliminate the latency of moving your hand to the mouse and clicking. Commands like "J" to scroll down feel instantaneous. Superhuman makes these shortcuts easy to learn and use.

Search Optimization

Most apps have notoriously slow search functions. But Superhuman optimized their fuzzy search algorithm to return results in an average of 50ms. Their zero-downtime indexing also prevents search delays.

Built for Speed

When you build an app from scratch, you can focus on speed as the #1 priority rather than bolting it onto an existing platform. Superhuman engineered the web architecture around performance.

UI Choices

Small UI decisions also enhance perceived speed – like avoiding infinite scroll which can cause lag when fetching content. The UI is clean and simple to render quickly.

The Need for Speed

Why optimize an app down to the millisecond level? To keep you in a state of flow.

In psychology, "flow" refers to a mental state of full immersion in an activity. You know the feeling – time seems to disappear because you‘re so focused.

But flow is fragile. Small interruptions like a laggy interface can disrupt this state of peak productivity.

By eliminating delays, Superhuman keeps you immersed and engaged during marathon email sessions. The faster your tools, the deeper your focus.

This is especially relevant for high-volume email power users. When blazing through hundreds of emails, those milliseconds saved on each interaction really add up. Even small delays feel frustrating.

Of course, the average person checking their personal email once a day won‘t notice minor speed improvements. But for professional users handling high email volumes, faster is better.

Who Needs This Level of Speed?

While Superhuman‘s speed is an engineering marvel, you might be wondering: is it necessary for me?

For light or personal email use, probably not. Gmail‘s 100-400ms latency is perfectly reasonable for opening a few emails in short sessions. Upgrading for a few saved milliseconds isn‘t worth a hefty subscription cost.

But for high-volume power users, Superhuman‘s speed can be a game changer by enhancing productivity and focus. Individual users who spend hours in their inbox daily will benefit the most. The optimizations keep you in flow.

However, entire teams are less likely to benefit. Superhuman is designed for personal productivity over collaboration. The mobile experience is limited, and core features like calendars and file sharing are missing. Companies are better off choosing a suite with more robust productivity tools.

In the end, obsessing over milliseconds comes down to your needs as an email user. The importance of speed depends on your workflow and email habits.

Do you want to experience the future of lightning-fast email? Give Superhuman‘s free trial a spin, and see if you gain enough efficiency to justify the premium subscription. But be warned – after using an app this fast, you may have a hard time going back to the sluggishness of Gmail!