Bring your own AI — ChatGPT, Claude, Gemini

You already have the AI.
We do the rest.

Paste the prompt, get a personalised workout program or meal plan back, import it, and track everything.

Download on the App Store

Free workouts forever · Nutrition unlock $9.99 USD
· No subscription. Ever.

"Every other AI fitness app is literally just ChatGPT with a massive markup. Found this app with a one time payment, handles all the tracking. Awesome."

★★★★★ christophol1337 · Australia

Watch how it works (44s)

01 Answer questions
→
02 Send to any AI
→
03 Import & track
Works with ChatGPTClaudeGeminiDeepSeek + any AI
Free Workout Programs

Your AI Workout Program
Is Ready.

Every aspect, optimised.

Full Year of Training

Up to 48 weeks. Mesocycles, training blocks, and deload weeks all built in.

Rest Times, Sorted

Rest periods assigned per exercise based on your goals and time available.

Any Training Split

Push/pull/legs, upper/lower, full body. Configured to your schedule.

Exercise Swaps

Machine taken? Every exercise has alternatives built in.

Volume Per Muscle Group

Every muscle group tracked and balanced across the week.

Any Goal, Any Level

Build muscle, lose fat, improve strength. Beginner to advanced.

See It Working

Real AI output.
Real programs.

Real output from a real user. ChatGPT, imported in 0.80s.

ChatGPT Output

AI verifies its own work before you import

The 3-step prompt pipeline asks the AI to review its own volume distribution, exercise selection, and progressive overload — then format for import. A checked program, not a first draft.

Workout imported in 0.80s Full training split with exercises Tracking sets and reps in a workout Swap exercises if machine is taken Progressive overload rep scheme by week
Full tutorial: 12-week hypertrophy with ChatGPT
Volume Verified

Muscle group balance, checked before you train

ChatGPT's output includes a per-muscle volume summary so you can verify the program is properly balanced.

Build Muscle 5 days/week Advanced 12–16 sets · Moderate Commercial Gym
Chest
13 sets
Quads
14 sets
Hamstrings
13 sets
Glutes
14 sets
Lats
12 sets
Upper Back
12 sets
Triceps
11 sets
Side Delts
10 sets
Biceps
10 sets
0.82s Import time — 33 movements, 4 weeks
48wk Max program length supported
How It Works

Three steps.
Infinite plans.

We build the prompt. You choose the AI. It's that simple.

01 — Quick Setup

Answer a few questions

Goals, schedule, experience, preferences. We build a perfect prompt customised for you.

02 — Send to Any AI

ChatGPT, Claude, Gemini

Paste the prompt, get a structured plan back in seconds. Whatever AI you like. Yes, it's a copy-paste step. It's also the reason you're not paying $20/month.

03 — Import & Train

Paste or upload the result

Your program loads instantly — every set, rep, meal, and macro ready to track.

Workout imports are free. Forever.

Import unlimited AI-generated workout programs. Track every exercise, set, rep, and weight. Multi-mesocycle programs up to 48 weeks. No paywall, no limits.

Download Free
$0
Unlock for $9.99 USD

Your AI Nutritionist
Is Ready.

Effortless eating, engineered for you.

AI Macro Engine

Precision protein, carbs, fat & fibre targets calibrated to your body and goals.

Smart Grocery Lists

Exact shopping lists. No confusion at the shops.

Meal Prep Blueprints

Step-by-step meal prep instructions for the week ahead.

Sleep-Synced Timing

Meal times optimised around your sleep for better recovery and energy.

Pantry Intelligence

Tell it what's in your fridge. Get plans that use what you already have.

Nutrition For Everyone

Dietitian-level personalisation. Unlimited plan changes. No appointments.

See It Working

Real AI output.
Real meal plans.

Real output from a real user. Claude, imported in 0.81s.

Claude Output

Your macros, calculated for your body and goal

The nutrition prompt pipeline takes your weight, goal, activity level, cooking style, and sleep schedule — and builds a complete 7-day plan with every macro accounted for.

Meal plan imported in 0.81s Daily meal timeline with macros Grocery list and meal prep schedule Itemised grocery list with prices Step by step meal prep session
Full tutorial: meal plan with Claude
Macros Verified

Every gram tracked. Every day covered.

Real output from a 7-day bulk plan generated with Claude. Macros calibrated to bodyweight, training volume, and assembly-only cooking preference.

Weight Gain 90kg · Male High Protein 6 meals/day Aldi · Canberra
Protein
229g
Carbs
368g
Fat
139g
Fibre
42g
3,629 kcal · Saturday
$230 weekly groceries · Aldi Canberra
Compare

Premium nutrition.
Accessible pricing.

Personalisation that used to require a professional — now available to everyone.

JSON.fit
Dietitian
Other Apps
Typical cost
$9.99 USD once
$150–300 USD/session
$20–60 USD/mo
Expert-level personalisation
✓
✓
Basic
Instant access
✓
Weeks wait
✓
Unlimited plan changes
✓
✗
✗
Grocery lists
✓
✗
✗
Meal prep guidance
✓
✗
✗
No ongoing fees
✓
✗
✗
AI provider choice
Yours
N/A
Locked in
★★★★★

"Every other AI fitness app is literally just ChatGPT with a massive markup. Found this app with a one time payment, handles all the tracking. Awesome."

christophol1337 · Australia
· No subscription. Ever.

Workouts free.
Unlock nutrition.

$9.99USD · one time

Own forever · No subscription

✓ Free: Unlimited AI workout imports
✓ Free: Full program & set tracking
✓ Free: No ads. Ever.
✓ AI meal plan generation & import
✓ Macro tracking & daily timeline
✓ Smart grocery lists & pantry intelligence
✓ Sleep-synced meal timing
✓ Works with ChatGPT, Claude, Gemini & more
Download on the App Store

🔒 Your data stays on your device. Always.

📱 iOS only · I want Android →

FAQ

Common questions.

How does it actually work?
The app builds a structured prompt based on your goals, schedule, and preferences. You copy it into any AI you already use — ChatGPT, Claude, Gemini, whatever. The AI generates a personalised plan. You paste the result back into JSON.fit and it loads instantly, ready to track.
Do I need to pay for AI separately?
Most AI chatbots have a free tier that works perfectly — ChatGPT, Gemini, and others all offer free access. If you're already paying for a premium AI subscription, even better. Either way, JSON.fit itself has no AI costs to pass on to you.
How much does JSON.fit cost?
Workouts are free forever — no paywall, no limits. Nutrition features (meal plans, macro tracking, grocery lists, meal prep, pantry intelligence) are a one-time $9.99 USD purchase. No subscription. You pay once and own it forever.
Why is it so much cheaper than other apps?
Most fitness apps charge $10–20/month because they run AI on their servers. JSON.fit uses the AI you already have, so there are no server costs to pass on to you. That's why workouts are free and nutrition is a one-time purchase.
What AI does it work with?
Any AI that can generate structured text — ChatGPT, Claude, Gemini, DeepSeek, and more. You're not locked into one provider. Use whatever you prefer.
Is my data private?
Yes. Your data stays on your device. JSON.fit doesn't have accounts, doesn't collect personal information, and doesn't send your workout or nutrition data anywhere.
Is it available on Android?
Not yet — it's currently iOS only. Android is in development. You can tap "I want it on Android" on this site to let us know there's demand.
Still not sure?

See a real meal plan before you commit.

A full walkthrough — from setup to Claude generating your macros, grocery list, and meal prep instructions. Imported in under a second.

Download Free Read the tutorial
✓ Noted — Android is coming!