Tool Guide

OpenAI Codex: Your Free AI Coding Tool

ChatGPT Free and Go users get free access until early April 2026

Mac Only (for now)
Free Until April

(Paid users get doubled rate limits for two months)

Watch the Full Tutorial

Complete walkthrough from download to deployment

What Is Codex?

OpenAI's coding assistant goes desktop

Codex is OpenAI's coding assistant. It's been around for a while as a cloud tool at chatgpt.com/codex, but what's new is the Mac OS desktop app.

So what?

The app represents a shift in how we interact with code. Traditional development environments (IDEs) show you all the code and expect you to work with it directly. Codex is different - it's more like chatting with ChatGPT. You describe what you want, it builds it.

It's less code-heavy. You can access the code behind the scenes, but you don't have to stare at it constantly.

The Big News:

Codex is free for ChatGPT Free and Go users until early April 2026. That's two months of free access to a proper AI coding tool. If you have a paid plan, your rate limit is doubled for the next two months.

The Catch:

Mac only for now. No Windows support yet.

How It Compares

Codex vs other AI coding tools

ToolCostEase of UseBest For
Lovable$25/monthEasiestComplete beginners who want instant results
Google AntigravityFreeMedium (looks like "real" IDE)Those comfortable with developer interfaces
Codex AppFree (for now)Medium (chat-based)Those who want ChatGPT-style interaction
Claude Code$200/month (Pro)TechnicalExperienced developers
Cursor$20/month + API costsMediumProfessional developers

Codex sits in a nice middle ground: chat-based interface (familiar), proper coding capabilities (powerful), free for two months (accessible).

The Two Barriers (And How to Overcome Them)

What makes Codex tricky for beginners

Heads up on the two barriers that make Codex a little trickier for beginners:

1. GitHub

You need this for version control and you'll need to set it up (even if you have no idea what GitHub is...)

2. Deployment

You need this to actually see your app. There's no built-in preview panel.

I spoke to the Codex team about making this easier for beginners. They confirmed: there are no plans for a built-in preview panel. You need to handle deployment yourself.

Don't worry - I'll show you the easiest way to handle both.

Step-by-Step Setup Guide

Follow along with the video for best results

1

Download the Codex Mac App

Go to chatgpt.com/codex and download the Mac OS app.

When you open it, you'll see a chat interface. If you've used ChatGPT, this will look familiar.

Download Codex
2

Create Your Project Folder

Click "New Thread" to start a new project.

Codex will ask you to create or select a folder. Create folder somewhere easy to find (like your Desktop):

Desktop → Projects → [Your App Name]

This folder is where all your project files will live.

3

Use Planning Mode

Before building anything, put Codex into planning mode:

Type /plan or just say "Can we plan this first?"

Why this matters: Without planning mode, AI models tend to rush off and start building before you've properly defined what you want. Planning mode keeps it in discussion mode.

Spend more time planning than building. The more work you do upfront, the better your application will be.

4

Describe Your App

Talk to Codex like you'd talk to a developer you're hiring. Describe:

  • What the app does
  • Who it's for
  • What screens/features you want
  • Whether it's a web app, mobile app, etc.

Example prompt:

"I want to build a web app that tracks daily activities and finds patterns over time. Users tap buttons to log what they did each day, then the app shows correlations between activities and their mood/energy levels."

Codex will ask clarifying questions. Answer them. This back-and-forth creates a detailed project plan. The more questions you answer, the better Codex will be able to build for you.

5

Choose Your Intelligence Level

Codex has three modes:

Medium

Faster, uses less capacity, good for simple tasks

High

Balanced

Extra High (Recommended for Planning)

Slower but more thorough, good for complex planning

Note: Extra High uses more of your daily capacity so use it for the most advanced tasks.

6

Let It Build

When planning is done, tell it to build: "ok let's build" or similar.

Be patient. Codex is slower than Claude Code. A task might take 20+ minutes where Claude Code would finish in a few minutes. But it's thorough! It's worth the longer time.

Pro tip: While one thread is building, you can start a new thread in the same project to work on something else. For example:

  • • Thread 1: Building the main app
  • • Thread 2: Creating a marketing landing page
  • • Thread 3: Working on a specific feature
7a

Preview Your App Locally

There's no easy "Preview panel" so Codex can't just show us the app we're building.

Pro tip: Just ask! Literally ask Codex "How do I preview this locally?"

It will give you terminal commands. The basic process will look like this:

# Open Terminal on your Mac (press Cmd+Space and type terminal)

# Navigate to your project folder:

cd Desktop/Projects/YourAppName

# Install dependencies:

npm install

# Start the dev server:

npm run dev

# Open your browser to:

http://localhost:3000

Don't panic about the terminal! It LOOKS scary. And it is the first time you see it. That's cool. If you get stuck, paste the error back into Codex and ask for help. You can also say "I don't understand that, give me a simpler way."

7b

Deploy with Vercel (Quick Method)

This is an alternative method. You can deploy your site/app to Vercel. Vercel is a hosting service where your app can "live" later.

Thankfully Codex has a Skill called Vercel Deploy. Click Skills then Vercel Deploy to add it to your project.

Then to trigger it in chat use /vercel or just ask for Codex to deploy to Vercel.

This will deploy to Vercel without you needing to make a Vercel account. Neat! It will create a public URL you can share.

You can also sign up for a Vercel account (free) and import your project. It's free to use until you reach a certain amount of traffic or usage. The free plan is generous though!

9

Connect GitHub (Important!)

GitHub is like cloud saves for your project. It keeps all previous versions, so if you break something, you can roll back.

The easiest method (no terminal required):

  1. 1.Create a free account at github.com
  2. 2.Download GitHub Desktop
  3. 3.Open GitHub Desktop
  4. 4.Click "Add" → "Add Existing Repository"
  5. 5.Find your project folder (Desktop → Projects → YourAppName)
  6. 6.Click "Add Repository"
  7. 7.Click "Publish Repository"

Done. Your project is now saved to GitHub.

Why bother?

  • Version history (undo mistakes)
  • Branching (test new features without breaking the live app)
  • Auto-deployment (connect GitHub to Vercel for automatic updates)
  • Collaboration (multiple people can work on the same project)

Alternative: You can also connect GitHub through the cloud version of Codex at chatgpt.com/codex. There's a dropdown to configure repositories directly.

10

Fix Errors

You've got your app preview up. You can play around with it. Kick the tyres.

Your app will have bugs. That's normal.

When you see an error:

  1. 1.Copy the error message (from the browser console or the app)
  2. 2.Paste it into Codex
  3. 3.Say "I have this error when going to [page name]"
  4. 4.Codex will find and fix it

Repeat until it works. This back-and-forth is the actual process of building software. This is the basic flow.

Hey! You're now vibe coding! Pretty cool huh?

Want to learn more about vibe coding? Check out this guide

Key Takeaways

Remember these points

Codex is free until early April

No excuse not to try it

Mac only for now

Windows support not yet available

Use planning mode

Spend more time planning than building

GitHub Desktop is the easiest way

Handle version control without the terminal

Ask Codex when stuck

It can explain things simply if you ask

Be patient

Codex is slower than Claude Code but thorough

Multiple threads

Work on different features simultaneously

Errors are normal

Copy, paste, fix, repeat

The Bigger Picture

Why this matters

I know people criticize AI coding - "you don't actually understand the real skills."

Ignore them.

This is a gateway to understanding those skills. By building stuff, you'll learn what GitHub is, what Vercel does, what a localhost is. You're learning by doing.

If you have an app idea, create it. The barrier has been removed.

Ready to Start Building?

Get Started with Codex Today

Join the daily AI news livestream where we dig into stories like this and you can ask questions directly.

OpenAI Codex Guide: Your Free AI Coding Tool (Mac Only) | AI with Kyle