HeyBLU: Baseball Strike Zone

Turn your iPhone into an objective source of truth. Get live audio ball/strike calls, command heatmaps, and elite player development tools. Start your 14-day free trial!

Every bullpen deserves BLU (Big League Umpire). Say "Hey", to HeyBLU.

HeyBLU turns your iPhone into an objective source of truth for youth baseball and fastpitch softball. Stop guessing. Start seeing every pitch. Mount your phone, set the zone, and get live audio “BALL” or “STRIKE” calls exactly as the pitch crosses the plate.

No expensive equipment, radar guns, or smart baseballs required. Just the iPhone you already carry. Built for the dirt field, HeyBLU works anywhere—no cell service or Wi-Fi needed.

FOR THE COST OF ONE GAME UMPIRE Imagine having a consistent, objective strike zone for every practice, scrimmage, and bullpen all year long—for the exact same price as hiring a single youth umpire for one game.

ESTABLISH COMMAND HeyBLU delivers the exact data pitchers and coaches need to build unshakeable confidence.

Live Audio Calls: Instant ball or strike audio via your iPhone, Bluetooth speaker, or earbuds.

Train to Your Zone: Fully adjustable strike zone height and width to perfectly match your league or age group.

Every Pitch Tells a Story: Objective heatmaps and pitch logs. Track plate-crossing locations, pitch counts, and estimated velocity to identify patterns and manage workloads.

Baseball & Fastpitch: Tailor the session to standard baseballs or 11-inch/12-inch softballs.

Follow Live: Share a live, read-only feed to a second device so coaches or parents can track locations directly from the dugout or stands.

BUILD BETTER BALLPLAYERS HeyBLU is a complete player development platform built for the youth game.

Own the Zone (Command Center): Sync a second device to select the intended pitch location before the throw. HeyBLU compares the actual result with the target to generate a command effectiveness rating.

Earn Your Innings: Track, save, and compare pitcher performance over time to prove exactly who hits their spots.

Solo Bullpens: Get instant audio feedback while throwing alone—no catcher or umpire needed.

Batter’s Eye Development: Give young hitters a consistent zone to build elite plate discipline instead of relying on “close enough” coaching angles.

Umpire Training: Give aspiring umpires an objective reference tool to train their eyes and evaluate their calls.

START YOUR 14-DAY FREE TRIAL Track your next bullpen completely free for 14 days. HeyBLU is just $4.99/month or $49.99/year in the U.S. and unlocks unlimited pitcher profiles, command heatmaps, saved reports, and data exports. Subscription auto-renews unless cancelled.