How long does it take to build a mobile app with AI? Real timings and costs from 12 test apps
About 6 minutes for a first build and 2 minutes per edit, measured on 12 test apps. Plus what a small AI-built app really costs.
Ilyos Olimov ·
Short answer: with AppX, a first version of a mobile app takes about 6 minutes of build time (median across 12 test apps, range 5 to 18 minutes). A change after that takes about 2 minutes. A small app costs roughly 9 to 30 credits to build, which is about $0.60 to $2 at Starter plan rates.
These are not marketing numbers. They come from a test run I did on September 27, 2026, plus real builds on the live site. Below is exactly how I measured them, what makes a build slower, and what it costs.
How long does it take to build an app with AI?
I keep a set of 12 different test apps that I build before every release. They cover the kinds of apps people actually ask for: a recipe box, a workout log, a pet care tracker, a hiring board, a private messenger, an AI chat app, a news digest, a queue system, a Russian-language warehouse CRM and more.
Each app gets built from scratch, then changed 3 times by chat ("add a settings screen", "change the colors", and so on).
Results from the last full run:
| App | First build | Edit 1 | Edit 2 | Edit 3 |
|---|---|---|---|---|
| Workout log | 5.0 min | 1.5 min | 1.9 min | 0.7 min |
| AI chat | 5.3 min | 2.4 min | 1.8 min | 0.8 min |
| Hiring board | 5.5 min | 3.0 min | 1.2 min | 0.7 min |
| Recipe box | 6.0 min | 3.6 min | 1.6 min | 0.7 min |
| Water delivery | 6.1 min | 3.5 min | failed | not run |
| Private messenger | 6.2 min | 3.3 min | 1.7 min | 0.8 min |
| Pet care log | 6.3 min | 2.6 min | 1.9 min | 0.8 min |
| Couples app | 7.0 min | 4.0 min | 1.9 min | 0.9 min |
| Warehouse CRM (Russian) | 7.3 min | 5.0 min | 2.0 min | 0.8 min |
| Queue system | 9.3 min | 3.5 min | 2.4 min | 0.8 min |
| News digest | 11.2 min | 3.3 min | 1.7 min | 0.9 min |
| Citizen media app | 18.0 min | 3.3 min | 1.9 min | 0.9 min |
- First builds: 12 out of 12 finished. Median 6.3 minutes, fastest 5.0, slowest 18.0.
- Edits: 34 out of 35 worked. Median 1.9 minutes, fastest 0.7, slowest 5.0. The one failed edit was a type error in the generated code that our checker now catches before saving.
What happens during those 6 minutes?
A first build is not one big AI call. It is a pipeline:
- Understanding your idea (about 30 to 40 seconds). AppX reads your description and, if something is unclear, asks you a short question, for example which part to build first.
- Planning the screens. You get a plan with the screens, the tabs and an estimate of the credits. Nothing is built until you approve it.
- Designing the look (about 1 minute). Colors, fonts and the basic components.
- Building the screens (most of the time). Each screen is written as real React Native (Expo) code, checked for errors, and fixed automatically if the check fails.
- Delivering the preview. The app is bundled so you can open it on your phone with Expo Go or in the browser.
The times in the table include all of that, but not the time you spend reading the question or the plan. In my tests the answers were automatic. For a real person, add however long you take to answer and press approve.
Why are some builds slower?
Most first builds landed between 5 and 7 minutes. A few took longer. Things that make a build slower:
- More screens and more logic. More files means more code to write and check.
- Automatic fixes. When generated code fails a check, AppX regenerates that file. You don't pay for these fixes, but they take time.
- Server load. When many builds run at the same time, delivering the preview can wait in a queue for a moment.
Edits are faster because only the changed files are rewritten. In my test the first edit was usually the slowest (often 3 to 4 minutes) because it was the biggest change. Small follow-ups take under a minute.
How much does it cost to build an app with AI?
AppX charges credits for what a build actually uses. Real examples from the live site:
| App | Screens | Credits |
|---|---|---|
| Water tracker (Sip) | 1 | 9 |
| Water reminder (SipDay) | 2 | 16 |
| Pet tracker | 4 | 26 |
| Recipe box (Crumbs) | 5 | 29 |
Edits are much cheaper. Small changes on the live site cost 3 to 6 credits each.
In money: on the Starter plan, $20 a month buys 300 credits, so one credit is about 7 cents. That makes the apps above roughly $0.60 to $2 each to build. Extra credits on paid plans cost $5 for 60. See the pricing page for current plans and discounts.
Two rules that matter for cost:
- You see an estimate before anything is built. The plan card shows "About N credits" and you approve it. In my latest test the estimate said 34 and the build charged 36.
- You are never charged more than your balance. If a build goes over, the extra is on me, not you.
For comparison, the usual way to get a first version of a mobile app is a freelancer or an agency, which normally means weeks of work and a much bigger budget. An AI builder doesn't replace a developer for everything, but for a first working version, the difference is minutes instead of weeks.
Is the result a real app?
Yes. AppX writes a real React Native project with Expo. You can:
- open it on your own phone with Expo Go,
- keep changing it by chat,
- download the full source code and give it to a developer,
- and when you are ready, publish it to the app stores.
Before you show it to real users, go through the 12-point launch checklist.
How to get a faster and cheaper first build
- Describe the app clearly. Name the screens and what each one does. This prompt template helps.
- Start small. Build the most important 3 to 5 screens first, then add more in milestones. Smaller builds are faster, cheaper and fail less.
- Answer the question quickly. If AppX asks you something, the build waits for you.
- Make edits one change at a time. "Change the main color to green" is faster and more reliable than five changes in one message.
How I measured this
- 12 test apps, each built from scratch on a staging server running the same code as the live site, then edited 3 times.
- Times are measured from sending the prompt to the preview being ready, with the question and plan answered automatically.
- Run date: September 27, 2026. Credit examples are real builds on appx.uz from September 2026.
- Prices are from the pricing page at the time of writing and can change.
FAQ
How long does it take to build a mobile app with AI? With AppX, the first version takes about 6 minutes of build time (median of 12 test apps, range 5 to 18 minutes), plus the time you take to answer one question and approve the plan.
How long does it take to change an AI-built app? About 2 minutes per change (median 1.9 minutes). Small changes often take under a minute.
How much does it cost to build an app with AI? On AppX, small apps cost about 9 to 30 credits to build, roughly $0.60 to $2 at Starter plan rates. You see an estimate before the build starts.
Can I keep the code? Yes. You can download the full React Native (Expo) source code and hand it to a developer.
Do I need to know how to code? No. You describe the app in normal words and change it by chat. If you can code, you can still download the project and continue in your own editor.
Written by Ilyos Olimov, solo founder of AppX. Numbers are from my own test runs and live builds. If you build an app and get very different times, tell me.