A decision for a beginner, not a spec sheet. Scores are our weights. Prices are the public plans, and anything marked verify on the tool page should be re-checked before you pay.
Pick Google Antigravity if you are trying an editor agent without a subscription.
Pick OpenAI Codex if you already pay for ChatGPT and want the coding agent in that allowance.
A free agent IDE, with higher quotas on Google AI Pro and Ultra.
Cheapest verified paid plan: Google AI Pro · $19.99/mo
A coding agent included with ChatGPT, not a separate app subscription.
Cheapest verified paid plan: Plus · $20/mo
Web app or SaaS
Mobile app
Game
Website or landing page
Automation or script
No code
I can follow a change
I already develop
Last verified 2026-10-19
Individual
Free
VerifiedUnlimited Tab and Command requests. Weekly agent quota. Gemini models, including Gemini 3.8 Flash, which the plans doc names as a core agent model. No published prompt count.
The Antigravity pricing page lists this at $0/mo.
Individual
$19.99/mo
VerifiedHigher Antigravity quota, refreshed every five hours until a weekly limit. AI credits can cover overage if you allow it. Also a Google One plan with storage and other Google AI benefits.
The dollar amount is the Google AI Pro price on Google One. Antigravity's own pricing page describes the higher limits and does not print $19.99.
Individual
$99.99/mo
VerifiedHighest Antigravity quota class, refreshed every five hours, plus third-party models. Google labels this 5x Pro Gemini usage.
Price is from Google One and Gemini subscription pages, which are the plans Antigravity docs say raise the quota.
Individual
$199.99/mo
VerifiedThe highest weekly limits Google documents for these plans, labeled 20x Pro Gemini usage.
Same source split as the 5x tier: quota rules on Antigravity docs, price on Google One.
Last verified 2026-10-19
Individual
Free
VerifiedLimited trial access to Codex and limited access to GPT-5.6. Codex pricing docs also list GPT-6 Luna at Standard speed in the desktop app, subject to rollout. No published prompt count.
Confirmed on the Codex pricing page as a limited trial. GPT-6 Luna on Free is listed as subject to rollout, so it is not treated as a guarantee.
Individual
Confirm on chatgpt.com/pricing
VerifyLimited Codex, above Free. Codex pricing docs at learn.chatgpt.com/docs/pricing list Go at $8/mo. chatgpt.com/pricing still did not print a dollar amount on 2026-10-19.
Left out of budget matching. The $8 figure is on a Codex pricing doc, and the live ChatGPT pricing page still does not show it.
Individual
$20/mo
VerifiedExpanded Codex for a few focused sessions a week. Codex app on macOS and Windows. Local and cloud usage share the allowance. Weekly limits may apply. GPT-6 Astra access is limited, with credits for more.
Plus is $20/mo on OpenAI's help center. Annual billing is not offered.
Individual
$100/mo
VerifiedHigher Codex allowance for longer daily sessions. GPT-6 Astra is included in the allowance. Ultrafast is not included.
From OpenAI's Pro tiers help article.
Individual
$200/mo
VerifiedMore included usage than Pro 100. Ultrafast is not included. New subscriptions may have a lower allowance than older Pro 200 accounts.
OpenAI says the monthly price remains $200.
Individual
$500/mo
VerifiedHighest included Pro usage. Ultrafast for GPT-6 Astra and GPT-6.1 Sol is included and draws the included allowance at 8× the Standard rate for that model.
Ultrafast is only on this Pro tier. The 8× rate is from OpenAI's Pro tiers help article.
Free quota refreshes weekly. Google AI Pro refreshes every five hours until a weekly limit. Ultra refreshes every five hours and has the highest weekly limits. Prompt counts are not published because heavier tasks spend more quota.
On the free plan, wait for the weekly refresh. There is no credit overage.
Plan allowance, with weekly limits that may also apply. Local messages and cloud chats share it. OpenAI does not publish one universal reset clock.
Switch to a lower-cost model. OpenAI says that stretches the same allowance.
Google Antigravity's cheapest paid plan the ranking counts is Google AI Pro at $19.99/mo. OpenAI Codex's cheapest paid plan the ranking counts is Plus at $20/mo.
Google Antigravity is for trying an editor agent without a subscription, gemini-first coding on a weekly quota, and a $20-ish step up via Google AI Pro if the free week runs out.
OpenAI Codex is for developers who already pay for ChatGPT and want the coding agent in that allowance, web apps and automations with local and cloud tasks, and a few focused coding sessions a week on Plus.
Google Antigravity scores 2 out of 5 for someone who does not want to read code. OpenAI Codex scores 1 out of 5. Google Antigravity has the higher no-code score. Better than a pure terminal, and you are still in an IDE. You are still in a coding agent. This is a poor pick if you never want to see a file.
Google Antigravity: Free. Unlimited Tab completions and Command requests, Gemini models, and a weekly agent quota. The quota is not a published prompt count. It refreshes weekly, not every five hours. OpenAI Codex: Free includes a limited Codex trial. OpenAI does not publish a fixed prompt count. It is enough to see the product, not to build through the month.