What it does
The shape of GPT-4 & Codex, in plain English.
OpenAI's GPT-4 is one of the most widely-used large language models, powering ChatGPT, Codex, and thousands of applications.
Why we like it
The parts that make us reach for it.
- General-purpose AI tasks
- Application development via API
- Code generation (Codex)
- Content creation at scale
- Plugin and tool ecosystems
When to use it
Match the tool to the job.
Each block below is a different day in the life of GPT-4 & Codex.
coding
Ship features, refactor code, and review diffs without leaving your editor.
writing
Draft long-form pieces with an honest voice; edit without losing your own.
automation
Wire up repeatable flows without glue-code bespoke per task.
agents
Keep a loop of reasoning + tool-use that doesn't spin forever.
What to watch out for
Where it gets in your way.
Not deal-breakers — just worth knowing before you commit.
- Can be verbose in responses
- Knowledge cutoff applies
- API costs at scale
- Rate limiting on free tier
Under the hood
Feature checklist.
GPT-4o multimodal model
Function calling / tool use
DALL-E image generation
Whisper speech-to-text
Assistants API with retrieval
Fine-tuning support
The bill
How much this will cost you.
Free tier with ChatGPT. Plus plan at $20/month. API: GPT-4o at $2.50/$10 per million tokens.