weyt.ai, in plain words.
A strength-training scoreboard. You log lifts in a few taps; it scores them the same way every time and ranks you against real people.
What it is
A free, web-based strength training app that installs on a phone (PWA; no app store listing yet). You build a workout or start from the one it loads for you, lift through it set by set or log it in two taps, and read the receipts: PRs, eight-week bests, the next targets posted to your plan. Every set feeds three deterministic scores, Gains, Balance and Routine, and a Weyt Age. No feed, no streak theater.
The math
Your Weyt Age is the age whose median strength matches your current bench press and squat, estimated from the sets you log (no max-out testing). The headline is ranked against the general population using the Cooper Institute bench-press norms published in the ACSM Guidelines for Exercise Testing and Prescription; the subline against lifters who track using Strength Level community standards. The squat is scored through its same-percentile bench equivalent, which keeps both lifts on one calibrated scale. The number reflects current form: old estimates are gently discounted, so a recent PR moves it down and time off drifts it up. Below the youngest published bracket the age is extrapolated from your percentile, down to 18. The three scores are computed only from your sets: Gains from e1RM trends per lift over eight weeks, Balance from 30-day sets per muscle group against monthly minimums, Routine from consistency against your weekly target. No AI touches a score.
The coach
The coach runs on Anthropic's Claude models and reads only your numbers. Once a week, and after every session, it reviews your board, commits to one change with a load, reps and a day, and says what would prove it wrong. The floating weyt button opens it for anything else, and the AI Workout Designer drafts a plan from your history. All of it is AI-generated fitness guidance, not medical advice.
Your data
Yours. No ads, nothing sold. The Weyt Age check on the landing page runs entirely in your browser. In the app, your training data is sent to Anthropic's API only to produce the coaching you asked for. Delete your account from Settings and everything goes with it. Details in the privacy policy.
Who
One lifter who ships frontier AI by day and lifts at night, from Sunnyvale, California. No growth team, no marketing budget, and no testimonials or counts on the site because none exist yet. Feedback you send through the coach lands with a human.