Flux (FLUX.2 [klein])
Free tier available
- FLUX.2 [klein] (Open-core)$0
- Flux.1 Schnell (legacy)$0
- FLUX.2 [max] / [pro] API$0.05/per image
![Flux (FLUX.2 [klein]) logo](/logos/flux.png)
Flux (FLUX.2 [klein])
Our pickCodex (OpenAI)
GPT-5.2-Codex (default 2026-04-23) / GPT-5.5 / GPT-5.4
Tier-list head-to-head. Codex (OpenAI) takes the A-tier slot — here's the breakdown.
Spec sheet
| Tier | B-tier | A-tierwin |
| Overall score | 7.8 / 10 | 8.3 / 10win |
| Powered by | — | GPT-5.2-Codex (default 2026-04-23) / GPT-5.5 / GPT-5.4 |
| Free tier | Yes | Yes |
| Starting price | $0 | $0 |
| Best for | Technically savvy users who want the best possible image quality and are willing to set up local inference. | Developers already paying for ChatGPT Plus who want a coding agent at no extra cost. |
| Last reviewed | 2026-04-17 | 2026-04-25 |
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 — Flux (FLUX.2 [klein]) 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.
Technically savvy users who want the best possible image quality and are willing to set up local inference. Also great for developers who want an open-source model they can fine-tune and deploy on their own infrastructure.
Visit Flux (FLUX.2 [klein])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)Bottom line
Codex (OpenAI) edges out Flux (FLUX.2 [klein]) by 0.5 points (8.3 vs 7.8) -- a A-tier vs B-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 (Flux (FLUX.2 [klein]) starts $0, Codex (OpenAI) 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 Flux (FLUX.2 [klein]) when technically savvy users who want the best possible image quality and are willing to set up local inference. Pick Codex (OpenAI) when developers already paying for chatgpt plus who want a coding agent at no extra cost. 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 Flux (FLUX.2 [klein])'s lane, the score gap matters less than the fit.
Bottom line: Codex (OpenAI) is the safer default for most readers, but Flux (FLUX.2 [klein]) is competitive enough that the tie-breaker is your specific workload, not the spec sheet.
Keep digging
Full Flux (FLUX.2 [klein]) review
Tier B · 7.8/10
Full Codex (OpenAI) review
Tier A · 8.3/10
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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.