ChatGPT Plus / Pro
$20 / $100–500 per mo
Models: OpenAI only (incl. Codex)
What "flat" means: Fixed price. Plus has a five-hour window (an estimated 15 to 160 GPT-6.1 Sol messages) and a weekly limit; Pro has no five-hour limit but still caps usage weekly. Codex local and cloud tasks share one allowance.
The catch: OpenAI models only, and weekly limits aren't published; parallel Codex tasks drain the shared allowance fast. Other agents can use the plan only through the Sign in with ChatGPT preview for open-source apps.
Pick ChatGPT Plus / Pro when
+You want the ChatGPT product itself alongside the coding agent
+OpenAI's cloud Codex tasks and managed sandboxes matter to your workflow
+OpenAI's GPT-6 models are your preference and the plan limits fit your volume
Cursor Premium / Ultra
$30 / $200 per mo (Plus $8, Super $100)
Models: Grok models included; third-party models billed separately
What "flat" means: Fixed price buying a weekly Grok usage pool sized as a multiple of Plus (Premium 4x, Super 15x, Ultra 50x), sold as a bundle with X Premium.
The catch: Claude, GPT and Gemini are not in the monthly price and bill separately at API list price, so outside Grok it is pay-as-you-go. Plus is Grok-only, and the pool's size in dollars or tokens isn't published.
Pick Cursor Premium / Ultra when
+You want the most polished AI-editor experience available
+In-editor Tab, chat, and agent in one tool outweighs raw usage volume
+Your monthly usage fits the plan's included value