OpenAI Codex code review vs Gemini Code Assist on GitHub
Both are AI pull-request reviewers with a verified GitHub bot. They share 1 Git platform. Facts come from each vendor's own pages; counts are public PRs created in 2026-W39 that each bot formally reviewed.
| Fact | OpenAI Codex code review | Gemini Code Assist on GitHub |
|---|---|---|
| Public PRs reviewed (rank) | 115,760 (#2) | 4,662 (#7) |
| Bot | chatgpt-codex-connector[bot] | gemini-code-assist[bot] |
| Category | Platform-native | Platform-native |
| Platforms | GitHub, GitLab | GitHub |
| Self-host | No | No |
| Licence | Proprietary | Proprietary |
| Pricing model | per-seat | free |
| Entry price | $20/seat/mo (ChatGPT Plus at $20/month is the cheapest plan listing cloud integrations such as automatic code review. Business is $25/user/month billed monthly ($20 annual, 2+ users). Usage counts against plan limits and can be extended with credits. API-key use has no GitHub code review. Free/Go list no code review for GitHub, while the GitLab beta page says it is 'available on all ChatGPT plans'. The Codex for OSS program is selective (by application).) | Free (Free while in Preview, but a Google Cloud billing account is required and Developer Connect usage above its free tier is billed. No post-Preview price is published. Gemini Code Assist Standard/Enterprise licences are a separate product, and since Sept 4, 2026 new subscriptions to them are sales-only.) |
| Free for open source | Not stated | Not stated |
| Free tier | Not stated | Yes |
| Sources | pricing · platforms (checked 2026-10-07) | pricing · platforms (checked 2026-10-07) |
A higher count means more observed public activity, not better reviews. See the methodology.