Maker of GPT-5 and the Codex family. OpenAI’s coding models on Kilo Code include GPT-5.5, GPT-5.1, GPT-5.1-Codex, and GPT-5.2. Use them across VS Code, JetBrains IDEs, Cursor, Windsurf, Trae, and the Kilo CLI — with pay-as-you-go pricing and no markup over the underlying provider rates.
Sorted by coding-index where published. Click any model for the full review with benchmarks, real-world Kilo usage, and provider-specific pricing.
OpenAI
GPT-5.5 is OpenAI’s frontier model designed for complex professional workloads, building on GPT-5.4 with stronger reasoning, higher reliability, and improved token efficiency on hard tasks. It features a 1M+ token...
OpenAI
GPT-5.1 is the latest frontier-grade model in the GPT-5 series, offering stronger general-purpose reasoning, improved instruction adherence, and a more natural conversational style compared to GPT-5. It uses adaptive reasoning...
OpenAI
GPT-5.1-Codex is a specialized version of GPT-5.1 optimized for software engineering and coding workflows. It is designed for both interactive development sessions and long, independent execution of complex engineering tasks....
OpenAI
GPT-5.2 is the latest frontier-grade model in the GPT-5 series, offering stronger agentic and long context perfomance compared to GPT-5.1. It uses adaptive reasoning to allocate computation dynamically, responding quickly...
OpenAI
GPT-5.2-Codex is an upgraded version of GPT-5.1-Codex optimized for software engineering and coding workflows. It is designed for both interactive development sessions and long, independent execution of complex engineering tasks....
OpenAI
GPT-5.3-Codex is OpenAI’s most advanced agentic coding model, combining the frontier software engineering performance of GPT-5.2-Codex with the broader reasoning and professional knowledge capabilities of GPT-5.2. It achieves state-of-the-art results...
OpenAI
GPT-5.4 is OpenAI’s latest frontier model, unifying the Codex and GPT lines into a single system. It features a 1M+ token context window (922K input, 128K output) with support for...
OpenAI is the lab behind the GPT family and the Codex coding-specialist line. GPT-5.5 is its most capable coding model in 2026; GPT-5.3-Codex and GPT-5.2-Codex are dedicated coding variants tuned for terminal and CLI work. OpenAI does not publish open weights for any GPT-class model; access is API-only.
Pay-as-you-go, no markup over the underlying provider rates. Cheapest first.
| Model | Input / 1M | Output / 1M | Context | Coding index |
|---|---|---|---|---|
| OpenAI: GPT-5.1 | $1.25 | $10.00 | 400K | 44.7 |
| OpenAI: GPT-5.1-Codex | $1.25 | $10.00 | 400K | 38.9 |
| OpenAI: GPT-5.2 | $1.75 | $14.00 | 400K | — |
| OpenAI: GPT-5.2-Codex | $1.75 | $14.00 | 400K | — |
| OpenAI: GPT-5.3-Codex | $1.75 | $14.00 | 400K | — |
| OpenAI: GPT-5.4 | $2.50 | $15.00 | 1050K | — |
| OpenAI: GPT-5.5 | $5.00 | $30.00 | 1050K | 58.5 |
Two ways: hosted in Kilo with no setup, or through your own provider keys.
The fastest path: install Kilo Code, sign in, pick openai from the model picker. No API keys, no markup. Works in VS Code, JetBrains, Cursor, Windsurf, Trae, and the Kilo CLI.
See live model leaderboard →Already have an account with OpenAI, OpenRouter, AWS Bedrock, Google Vertex, Together AI, or another compatible provider? Plug your key into Kilo Code and keep your existing billing relationship.
BYOK setup guide →See coding-model lineups from OpenAI’s closest competitors.
OpenAI’s flagship is among the strongest coding models on the Kilo Code leaderboard, ranked by Code, Plan, Ask, Debug, and Review usage.
VS Code, Cursor, Windsurf, Trae, JetBrains IDEs (IntelliJ, PyCharm, WebStorm, GoLand, RubyMine, Android Studio), and the Kilo CLI / terminal.
Switch between OpenAI and 500+ other models with one click. Pay only for what you use, at the underlying provider rate.
GPT-5.5 is the strongest general-purpose OpenAI coding model on Kilo Code today. For sustained terminal and CLI tasks, GPT-5.3-Codex is the dedicated coding variant. GPT-5.4 is the workhorse mid-tier; GPT-5.1-Codex is a cheaper coding-tuned option.
Every OpenAI model works in all Kilo-supported surfaces: VS Code, Cursor, Windsurf, Trae, JetBrains IDEs, and the Kilo CLI / terminal.
OpenAI models on Kilo Code are billed at the underlying API rates with no markup. GPT-5.5 starts at $5.00 per million input and $30.00 per million output. GPT-5.4 is roughly $2.50 / $15. GPT-5.3-Codex is $1.75 / $14. GPT-5.1 is $1.25 / $10.
No. OpenAI does not publish weights for any production GPT-5 or Codex model. All access is API-only. Kilo Code supports OpenAI directly, plus Azure OpenAI as an alternate gateway.
GPT-5.5 is the largest, smartest, and most expensive frontier model. GPT-5.4 is the everyday balanced option. GPT-5.3-Codex and GPT-5.2-Codex are reinforcement-tuned for terminal coding agents — stronger on tool use and long shell sessions, slightly weaker on pure reasoning.
Every OpenAI model works in all Kilo-supported surfaces: VS Code, Cursor, Windsurf, Trae, JetBrains IDEs, and the Kilo CLI / terminal.
Install Kilo Code and get instant access to OpenAI: GPT-5.5 and 6 other OpenAI models, plus 500+ frontier and open-source options. Free to start, no credit card required.