Codex (OpenAI)
Free tier available
- Free$0
- Go$8/mo
- Plus$20/mo
Our pickCodex (OpenAI)
GPT-5.2-Codex (default 2026-04-23) / GPT-5.5 / GPT-5.4

Google Antigravity
Gemini 3.1 Pro / Claude Opus 4.6 / GPT-OSS 120B (multi-model)
Tier-list head-to-head. Codex (OpenAI) takes the A-tier slot — here's the breakdown.
Spec sheet
| Tier | A-tierwin | A-tier |
| Overall score | 8.3 / 10win | 8.0 / 10 |
| Powered by | GPT-5.2-Codex (default 2026-04-23) / GPT-5.5 / GPT-5.4 | Gemini 3.1 Pro / Claude Opus 4.6 / GPT-OSS 120B (multi-model) |
| Free tier | Yes | Yes |
| Starting price | $0 | $0 |
| Best for | Developers already paying for ChatGPT Plus who want a coding agent at no extra cost. | Developers working on large, multi-file projects who want to parallelize their workflow. |
| Last reviewed | 2026-04-25 | 2026-04-14 |
Head-to-head
Rated 1-10 on the same rubric across all 130 tools we cover.
What you'll pay
Look past the headline number -- entry-tier limits drive most cost surprises.
Free tier available
Free tier available
GPT-5.2-Codex (launched 2026-04-23 -- SOTA on SWE-Bench Pro and Terminal-Bench 2.0; first-party scores below pending detailed third-party verification) benchmarks — Google Antigravity has no published benchmarks
| Benchmark | Description | Score |
|---|---|---|
| SWE-bench | Real GitHub issue fixing | 72% |
| HumanEval | Python code generation | 95% |
The decision
Use-case anchors and category strengths, side by side.
Developers already paying for ChatGPT Plus who want a coding agent at no extra cost. Especially good for parallel task execution -- assign multiple bug fixes or feature branches and let Codex work them simultaneously.
Visit Codex (OpenAI)Developers working on large, multi-file projects who want to parallelize their workflow. If you regularly work on 3-5 tasks simultaneously (fix a bug, add a feature, write tests, refactor), Antigravity's multi-agent architecture is unmatched.
Visit Google AntigravityBottom line
Codex (OpenAI) edges out Google Antigravity by 0.3 points (8.3 vs 8.0) -- a A-tier vs A-tier split that's narrow but real. Not a blowout; both belong on a shortlist. The score gap shows up most clearly in the categories that matter for Codex (OpenAI)'s strengths, so if those categories are your priority, the lead translates.
Pricing-wise, both tools have a free tier (Codex (OpenAI) starts $0, Google Antigravity starts $0), so you can test either without committing. Compare what each free tier actually unlocks -- usage caps, model access, and feature gates differ a lot more than the headline price suggests, especially as both vendors have tightened limits in 2026.
By use case: pick Codex (OpenAI) when developers already paying for chatgpt plus who want a coding agent at no extra cost. Pick Google Antigravity when developers working on large, multi-file projects who want to parallelize their workflow. The two tools aren't fighting for the same person -- they're aiming at adjacent jobs that occasionally overlap. If you're squarely in Codex (OpenAI)'s lane, the tier-list ranking and the use-case fit point the same direction; if you're in Google Antigravity's lane, the score gap matters less than the fit.
Bottom line: Codex (OpenAI) is the safer default for most readers, but Google Antigravity is competitive enough that the tie-breaker is your specific workload, not the spec sheet.
Keep digging
Full Codex (OpenAI) review
Tier A · 8.3/10
Full Google Antigravity review
Tier A · 8.0/10
Codex (OpenAI) alternatives
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Google Antigravity alternatives
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Built from our daily AI-tool sweep, last touched April 25, 2026. Honest tier-list reviews — no affiliate-link pieces disguised as advice. See the rubric or how we review.