Side-by-side comparison · Coding & Dev Tools
Google Antigravity vs Kiro vs OpenAI Codex
Everything that matters when choosing between them, in one place: our rating, what each can do, what they cost, and the trade-offs.
Comparing 3 tools, the maximum.
At a glance
Pick it if: Google AI Pro subscribers, and anyone who wants to try handing coding work to AI agents for free.
Pick it if: Developers and technical founders who want a written plan before the AI builds anything, especially teams already on AWS.
Pick it if: ChatGPT subscribers who want a coding agent without paying for a second subscription.
Overview
| Attribute | Google Antigravity | Kiro | OpenAI Codex |
|---|---|---|---|
| In one line | Google's free coding app. You hand tasks to AI agents and review what they produce. | Amazon's AI code editor that writes a plan and requirements before it writes any code. | OpenAI's coding agent. Hand it a task and it works away while you do other things. |
| Pricing model | Freemium | Freemium | Freemium |
| Starting price | $19.99/mo | $20/mo | $8/mo |
| Free plan | Yes | Yes | Yes |
| Works with Claude Code | No | Yes | No |
Rating breakdown
Our scores out of 5. The higher bar in each row is highlighted.
| Attribute | Google Antigravity | Kiro | OpenAI Codex |
|---|---|---|---|
| Overall rating | 3.9 | 3.6 | 4.2Winner |
| Ease of useHow quickly someone non-technical gets value from it. | 3.5 | 4.0 | 3.5 |
| FeaturesHow completely it covers its own job, and how well the pieces fit together. | 4.0 | 4.5 | 4.5 |
| Output qualityHow good the results are before you fix them. | 4.0 | 3.5 | 4.5 |
| Value for moneyWhat you get for the price, including the free plan. | 4.5 | 3.0 | 4.5 |
| Speed & reliabilityHow fast it is and how often it falls over. | 3.5 | 3.0 | 4.0 |
Feature comparison
A tick means it does this today. A dash means we haven't checked.
| Attribute | Google Antigravity | Kiro | OpenAI Codex |
|---|---|---|---|
| Access & platform | |||
| Free plan | Yes | Yes | Yes |
| Mobile app | No | Yes | Yes |
| Desktop app | Yes | Yes | Yes |
| Browser extension | Yes | No | No |
| API access | Yes | No | Yes |
| Teams & business | |||
| Team workspace | Yes | Yes | Yes |
| Enterprise plan or SSO | Yes | Yes | Yes |
| Connects to other apps | Yes | Yes | Yes |
| Open source or self-hosted | No | No | Yes |
| AI abilities | |||
| Works with your files | Yes | Yes | Yes |
| Understands images | Yes | Yes | Yes |
| Makes images | Yes | No | No |
| Makes video | No | No | No |
| Writes code | Yes | Yes | Yes |
| Runs agents or automations | Yes | Yes | Yes |
| Learns your brand or style | Yes | Yes | Yes |
| Works in many languages | Yes | Yes | Yes |
| Capabilities score | 14/ 17 | 12/ 17 | 14/ 17 |
Pricing
Plans as listed on each vendor's site when we last checked. Confirm before you buy.
| Attribute | Google Antigravity | Kiro | OpenAI Codex |
|---|---|---|---|
| Plans | IndividualOur pick Free Trying agent-based coding without paying. | Free Free Trying spec mode on a small project. | Free Free A quick look at what it can do. |
Google AI Pro $19.99/mo People who already have or want the Google AI Pro bundle. | ProOur pick $20/mo Most individuals using it a few days a week. | Go $8/mo Occasional light tasks. | |
Google AI Ultra From $99.99/mo Developers who want Antigravity as a daily driver. | Pro+ $40/mo Regular daily users. | PlusOur pick $20/mo Anyone who already pays for ChatGPT. | |
Business (via Google Cloud) From $30/seat/mo Companies already on Google Cloud. | Pro Max $100/mo Professionals in Kiro for hours each day. | Pro From $100/mo Developers who hit the Plus limits. | |
Power $200/mo The heaviest users. | Business $20/user/mo billed yearly, or $25 monthly Teams of 2 or more. | ||
Enterprise Custom Companies that need SSO and central billing. | Enterprise Custom Large organisations. | ||
| Which plan to pick | Start on the free Individual tier; it is the whole point. If you hit the weekly limits and you also use Gemini for other things, Google AI Pro at $19.99 is a sensible step. Ultra only makes sense for full-time developers. | Pro at $20 is the place to start, and you get $20 off your first paid month when you upgrade. Use the Auto model to make credits last, and only move up a tier once you know your monthly usage. | If you already have ChatGPT Plus, you have Codex: just try it. If you are choosing between this and Claude Code with no existing subscription, Plus at $20 and Claude Pro at $20 cost the same, so pick whichever chat assistant you prefer. If you outgrow Plus, Pro starts at $100 and has no five-hour limit for now. The $200 tier gives new subscribers less usage than it used to, and Ultrafast mode is only on the $500 tier. |
Key features
| Attribute | Google Antigravity | Kiro | OpenAI Codex |
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Pros and cons
| Attribute | Google Antigravity | Kiro | OpenAI Codex |
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Who each one is for
| Attribute | Google Antigravity | Kiro | OpenAI Codex |
|---|---|---|---|
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Questions people ask
Which is better, Google Antigravity, Kiro or OpenAI Codex?
OpenAI Codex scores highest overall in our ratings (Google Antigravity 3.9/5, Kiro 3.6/5 and OpenAI Codex 4.2/5). Google Antigravity is best for Trying AI coding agents for free and running several agents at once. Kiro is best for turning a rough idea into requirements and a plan and bigger features you want planned before building. OpenAI Codex is best for background tasks in the cloud and starting a task from your phone.
Which is cheaper, Google Antigravity, Kiro or OpenAI Codex?
Google Antigravity: There's a free plan, and paid plans start at $19.99/mo. Kiro: There's a free plan, and paid plans start at $20/mo. OpenAI Codex: There's a free plan, and paid plans start at $8/mo.
Which is easier to use, Google Antigravity, Kiro or OpenAI Codex?
Kiro rates highest for ease of use in our scores. Developers and technical founders who want a written plan before the AI builds anything, especially teams already on AWS.
How we compare
Ratings are our own, from using each tool, across ease of use, features, output quality, value for money, speed & reliability.
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