ChatGPT
OPT
Pricing
PricingFreemium
PricingOpen Source
Free Plan
Free Plan
Free Plan
Side-by-side comparison based on pricing, features, and community data.
ChatGPT and OPT are both AI writing tools. ChatGPT is Freemium; OPT is Open Source. ChatGPT Writer and OPT serve fundamentally different buyers.
ChatGPT Writer and OPT serve fundamentally different buyers. ChatGPT Writer is a productivity tool for professionals who write emails and messages daily — it's browser-based, ready to use, and integrates directly into Gmail. OPT is a research-grade language model for developers and ML researchers who need to build or fine-tune their own applications. ChatGPT Writer wins for end-users seeking immediate email efficiency; OPT wins for teams deploying custom NLP systems on their own infrastructure. They're not competitors — they target opposite audiences.
Pick ChatGPT Writer if you send dozens of emails daily and want AI-drafted replies without leaving Gmail.
Pick OPT if you're a researcher or engineer building a custom language model application and need reproducible, open-source code.
| Feature | ChatGPT | OPT |
|---|---|---|
| User Interface | Browser extension, inline drafting | API / code library only |
| Email Integration | ✓ Native Gmail context-reading | — |
| Language Support | 20+ languages | English only |
| Deployment | Pre-built, zero setup | Self-hosted, requires ML infrastructure |
| Customization | Custom writing style instructions | Full fine-tuning on your data |
| Free Access | Freemium with daily limits | Open-source, unlimited (self-hosted) |
| Browser Support | Chrome only | Any environment with Python/PyTorch |
Synthesized by AI from verified tool data · cached per pair
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