Coding · Head-to-head
OpenAI Codex vs GLM-5.2
OpenAI Codex vs GLM-5.2: pricing, features, and which to pick in 2026.
The verdict
Pick OpenAI Codex if…
- →your primary use case is teams already standardised on chatgpt who want the coding agent bundled with the seats they pay for, and who want the same agent in a terminal, an editor and a pull request.
- →you need: productivity
Pick GLM-5.2 if…
- →you want our editor's pick for this category
- →your primary use case is development teams building coding agents who want a frontier-class model they can self-host, fine-tune, and deploy under a fully permissive license.
Side-by-side specs
| Spec | OpenAI Codex | GLM-5.2 |
|---|---|---|
| Category | Coding | Coding |
| Pricing model | freemium | freemium |
| Headline pricing | Included with ChatGPT Free, Go, Plus, Pro, Business, Edu and Enterprise plans | Free 20M tokens on signup + open weights; paid API & coding plans (check site) |
| Free tier | Yes. OpenAI documents Codex as included on the ChatGPT Free plan, with access described as restricted to basic tasks. | Free chat access plus 20M free tokens on API signup, and open weights available to download and self-host under MIT. |
| AI Score | 8.8/10 | 8.7/10 |
| Best for | Teams already standardised on ChatGPT who want the coding agent bundled with the seats they pay for, and who want the same agent in a terminal, an editor and a pull request. | Development teams building coding agents who want a frontier-class model they can self-host, fine-tune, and deploy under a fully permissive license. |
| Editor's pick | — | ✓ Yes |
| Use cases | development agents productivity | development agents |
| Date added | 2026-08-02 | 2026-06-27 |
Pros and cons
🧑💻
OpenAI Codex
Coding · freemium
Pros
- ✓Included in ChatGPT plans from the free tier upward, so most organisations already own it
- ✓Covers the terminal, the editor, a hosted cloud runner, the ChatGPT apps and GitHub pull request review from one entitlement
- ✓AGENTS.md keeps agent configuration in the repo and under version control rather than in someone's local settings
- ✓Three GPT-5.6 variants let a team route cheap work to Luna and hard work to Sol instead of paying one rate for everything
- ✓Overflow credits are priced per million tokens, which makes the marginal cost of extra work legible
Cons
- ×Published limits are ranges per rolling five-hour window that span two orders of magnitude, so the included allowance is not knowable in advance
- ×Usage depends on which model variant a task routes to, and routing is not fully under the user's control
- ×Pro pricing is presented as tiers rather than a single figure, so the real cost of the heavy plan needs checking at the point of sale
- ×The agent is tied to a ChatGPT account, which is awkward for teams that standardised on a different assistant vendor
GLM-5.2
Coding · freemium
Pros
- ✓MIT-licensed open weights — full commercial use, self-hosting, and fine-tuning with no revocable API terms
- ✓1M-token context handles whole codebases and long agent histories in one pass
- ✓Benchmark results competitive with top closed frontier models, especially on coding and agentic tasks
- ✓Genuinely free to start: chat UI, 20M signup tokens, or download the weights
- ✓Strong fit for coding agents thanks to its long-horizon, tool-use orientation
Cons
- ×At 744B parameters, self-hosting demands serious GPU hardware — out of reach for most individual developers
- ×Vendor-published benchmarks need independent verification; real-world coding performance may vary from the claims
- ×Hosted API and coding-plan pricing isn't transparently listed, so budgeting requires checking the site
- ×As a model from Zhipu AI, some enterprises face data-residency or procurement constraints around China-based providers
Related comparisons
Updated 2026-08-02. Spec data sourced from official product pages and tracked in our public directory at /tools.