Codex (OpenAI)
Free tier available
- API -- gpt-6.1-sol (2026-09-29)$2/$10/per 1M tokens; cached input $0.10 (GPT-6 Sol: $0.20)
- API -- gpt-6.1-terra (2026-10-26)$1/$5/per 1M tokens; cached input $0.05
- Free$0
Our pickCodex (OpenAI)
GPT-6.1 Sol (added 2026-09-29 for Plus and up, rolling out from Pro; Ultrafast variant coming) + GPT-6 Sol + GPT-6 Luna (2026-09-22; Luna for Free/Go in the desktop app) + GPT-6 Astra (Ultrafast tier on Pro 500/Enterprise) alongside GPT-5.6 Sol / Terra / Luna (GA 2026-07-09; Terra default on Free/Go). GPT-5.5 remains selectable as previous-gen; GPT-5.4 retired from Codex 2026-08-31; GPT-5.2-Codex retired 2026-07-23; gpt-5.3-codex leaves the API 2027-04-01

Codestral (Mistral)
Tier-list head-to-head. Codex (OpenAI) takes the A-tier slot — here's the breakdown.
Spec sheet
| Tier | A-tierwin | B-tier |
| Overall score | 8.3 / 10win | 7.0 / 10 |
| Powered by | GPT-6.1 Sol (added 2026-09-29 for Plus and up, rolling out from Pro; Ultrafast variant coming) + GPT-6 Sol + GPT-6 Luna (2026-09-22; Luna for Free/Go in the desktop app) + GPT-6 Astra (Ultrafast tier on Pro 500/Enterprise) alongside GPT-5.6 Sol / Terra / Luna (GA 2026-07-09; Terra default on Free/Go). GPT-5.5 remains selectable as previous-gen; GPT-5.4 retired from Codex 2026-08-31; GPT-5.2-Codex retired 2026-07-23; gpt-5.3-codex leaves the API 2027-04-01 | — |
| Free tier | Yes | Yes |
| Starting price | $2/$10 | $0.30 / $0.90 |
| Best for | Developers already paying for ChatGPT Plus who want a coding agent at no extra cost. | Developers and teams who want a cheap, low-latency FIM model for IDE autocomplete via API, or enterprises t… |
| Last reviewed | 2026-11-05 | 2026-11-02 |
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 (HISTORICAL -- this model was RETIRED 2026-07-23; scores retained for trend context only). GPT-6 Sol and Luna joined Codex 2026-09-22: OpenAI reports DeepSWE v1.1 68.8% (Sol, max effort) and 66.6% (Luna, max) -- first-party, third-party verification pending; see Known Issues benchmarks — Codestral (Mistral) 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 and teams who want a cheap, low-latency FIM model for IDE autocomplete via API, or enterprises that want Mistral's coding stack deployed in their own VPC or on-prem, particularly those with EU vendor or data-residency preferences. Good for in-house IDE extensions, code-review bots, or CI/CD AI integrations.
Visit Codestral (Mistral)Bottom line
Codex (OpenAI) is the clear winner: 8.3/10 (A-tier) versus 7.0/10 (B-tier). Codestral (Mistral) isn't a bad tool, but on every category that drives the overall score, Codex (OpenAI) comes out ahead. The tier gap is repeatable -- not methodology noise -- and the day-to-day experience reflects it.
Pricing-wise, both tools have a free tier (Codex (OpenAI) starts $2/$10, Codestral (Mistral) starts $0.30 / $0.90), 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 Codestral (Mistral) when developers and teams who want a cheap, low-latency fim model for ide autocomplete via api, or enterprises that want mistral's coding stack deployed in their own vpc or on-prem, particularly those with eu vendor or data-residency preferences. 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 Codestral (Mistral)'s lane, the score gap matters less than the fit.
Bottom line: Codex (OpenAI) is the better tool for most people right now. Pick Codestral (Mistral) only when developers and teams who want a cheap, low-latency fim model for ide autocomplete via api, or enterprises that want mistral's coding stack deployed in their own vpc or on-prem, particularly those with eu vendor or data-residency preferences -- that's its lane, and inside that lane it still earns its place.
Keep digging
Full Codex (OpenAI) review
Tier A · 8.3/10
Full Codestral (Mistral) review
Tier B · 7.0/10
Codex (OpenAI) alternatives
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Codestral (Mistral) alternatives
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Built from our daily AI-tool sweep, last touched November 5, 2026. Honest tier-list reviews — no affiliate-link pieces disguised as advice. See the rubric or how we review.