Starting out? Hit a plateau? Chasing 1550? Starting out? Hit a plateau? Chasing 1550?

The Complete SAT® Prep — With a Coach Built In

Every question crafted to feel like the real SAT.
Every session adapts to your level.
JAX — your personal SAT coach — finds your weak spots across 120+ question patterns and builds your daily plan to hit your target score.

No credit card required · Includes full JAX coaching, unlimited practice, 4 section tests & 1 full-length test

📚
10,000+ Questions
📝
20 Full-Length Tests
♾️
Unlimited Section Tests
💲
$69 One-Time
🚫
No Subscriptions
J.A.X. Daily Briefing
Pick any task to start · the rest carry forward
Actions for Alex · Feb 10, 2026
Section Test
Math — Module 2 (Hard)

Your performance is trending up at 84% accuracy across the questions you've practiced, which puts you in position to tackle the harder module and push toward mastery of advanced patterns.

30 min
Start →
Practice · English
Central Ideas & Details

Your accuracy on Easy "Central Ideas & Details" questions is dragging you down.You're struggling with questions that ask you to distill a passage into a single overarching statement identifying the primary subject.

20 min
Start →
Practice · Math
Equivalent Expressions

You still need to practice all question patterns here. You're missing exposure to questions requiring the distributive property and combining like terms to simplify polynomial expressions.

20 min
Start →
// J.A.X. Stay Locked In.

Fastest Path to your Target Score

No guesswork. No random practice. JAX builds your plan and adjusts it every day based on your progress.

1

Take Your Diagnostic

Start with a diagnostic test. JAX maps your strengths and weaknesses across every question pattern on the Digital SAT.

2

Get Your Personal Plan

JAX creates a custom study plan based on your results and target score. Each day, you get 3 focused tasks designed for maximum impact.

3

Practice with Purpose

Every question is chosen based on your current level. As you improve, the difficulty adapts to keep pushing you forward.

4

Track & Level Up

JAX tracks your mastery of 120+ patterns in real time. It tells you when to test, when to review, and when you're ready.

Stop Practicing Randomly.
Start Preparing Strategically.

Most SAT Prep Platforms

Hand you a question bank and say "go practice"

Questions served without knowing your level

You decide what to study and when to test

Track overall scores only

One-size-fits-all difficulty

JustLockedIn with JAX

Builds your daily plan and tells you exactly what to do next

Every question chosen based on your performance data

JAX sequences your tests and tells you when you're ready

Tracks mastery across individual topics and 120+ specific SAT patterns

Adapts difficulty in real time to your exact level and pushes your higher

Everything You Need. Nothing You Don't.

Every plan includes full access to JAX coaching and every feature below.

🎯

JAX Coaching Engine

Your personal coach that builds daily tasks, adapts to your progress, sequences your tests, and finds the fastest path to your target score.

📚

10,000+ Authentic Questions

Every question mirrors how the real Digital SAT works. Organized by 120+ patterns so you master the method, not just the answer.

📝

20 Full-Length Adaptive Tests

Calibrated to match Bluebook® tone, structure, difficulty, and pacing with real multistage adaptivity between modules.

⏱️

Unlimited Section Tests

Focused 30-minute tests for Reading & Writing or Math. Choose Module 1 or Module 2 to target specific difficulty levels.

💡

Step-by-Step Explanations

Learn how to solve every type of problem — not just what the right answer is, but why the wrong ones are designed to trap you.

🖥️

Bluebook®-Matched Interface

Desmos calculator, reference sheets, annotation tools, timer, and answer eliminator. The exact environment you'll test in.

Built to Feel Like Test Day

Digital SAT test interface with timer, Desmos calculator, and Bluebook®-matched UI

Seamless Test-Day Experience

Our platform mirrors the official Digital SAT interface — including the on-screen timer, embedded Desmos calculator, digital reference sheets, annotation tools, and answer eliminator. Practice in the exact environment you'll test in, so nothing surprises you on test day.

LockedIn Score™ — performance by domain, pattern mastery, score tracking

Know Exactly Where You Stand

The LockedIn Score goes deeper than a practice test number. It measures consistency, difficulty progression, and pattern coverage — so you know how ready you actually are for test day, not just how you scored on one practice run.

Step-by-step answer explanation with wrong answer analysis

Go Beyond the "Right" Answer

Don't just learn what the right answer is. Learn why. Our step-by-step explanations show you how to solve each problem — often in multiple ways — and explain why the wrong answers are designed to trap you. This is how you stop repeating mistakes.

Raise the Score, Not Your Budget

All plans include full JAX coaching and every feature.

One-time payment · No subscriptions · No recurring charges
SAT® Foundation
3 months
$69
one-time
Perfect for students with 3 months until test day. Master key concepts and build confidence.
Buy Now
SAT® Mastery
12 months
$199
one-time
Best for students aiming for 1500+. Deep, long-term practice to master every pattern.
Buy Now

Try everything free for 7 days — including full JAX coaching, 4 section tests, and 1 full-length test you keep forever.

Get Started for Free →

No credit card required

Built on Math, Not Marketing

JustLockedIn was built by an engineer who deconstructed the Digital SAT into its core architecture. The same question patterns repeat in every test — just with different content and numbers. JAX uses precise statistical modeling to track your mastery of each pattern and calculate the most efficient path to your target score.

120+
Question Patterns
10K+
Practice Questions
20
Full-Length Tests

💚 Our Commitment to Access

We believe every student deserves high-quality SAT prep, regardless of family budget. If your student qualifies for a free or reduced-price school lunch program, they can receive full free access to our 6-month Momentum plan. Create a free account, try the platform, then email [email protected] with proof of eligibility. We'll upgrade your account at no cost.

Frequently Asked Questions

JAX is your personal SAT coach built into JustLockedIn. It analyzes your performance, builds your daily study plan, selects the right questions for your level, and tells you when to take section tests and full-length exams. Think of it as a private tutor who knows exactly where you need to focus — available every time you log in.

JAX uses statistical modeling across 120+ Digital SAT question patterns to identify where you'll get the biggest score improvements. Each day, it creates 3 focused tasks (~20 minutes each) designed to close your most impactful gaps.

Free resources give you questions but leave you to figure out what to study, when, and how. JustLockedIn with JAX coaches you through the entire process — building your plan, adapting your practice, and sequencing your tests for optimal preparation. You can use both together: Khan Academy for content review and JustLockedIn for structured, coached practice.

Yes. JAX calibrates to each student's starting point and target score. Whether your student is working toward 1100 or 1550, JAX builds the right path.

7 days of full access to JAX coaching, unlimited adaptive practice, 4 section tests, and 1 full-length adaptive test. No credit card required. After the trial, you keep the 4 section tests and 1 full-length test permanently, even if you don't purchase a plan.

Yes. All plans are one-time payments with no subscriptions, no auto-renewals, and no recurring charges. You get full access to everything — including JAX — for the duration of your plan.

That's why we offer the free trial — so you can try everything before committing. Please review the Terms and Conditions for details on our refund policy.

Yes. JustLockedIn works on any device with a modern web browser. Your progress syncs automatically so you can practice on your laptop at home and your tablet at school.