GPT-5 vs Grok 4
chatThis page puts OpenAI: GPT-5 and xAI: Grok 4 next to each other so you can check specs and run both in one place on Rewind.ai.
Specs compared
| GPT-5 | Grok 4 | |
|---|---|---|
| Provider | OpenAI | xAI |
| Category | chat | chat |
| Context window | 400000 tokens | 256000 tokens |
| Cost per messageRewind.ai tokens (estimate) | ~4,078 tokens | ~6,750 tokens |
| Free to use without purchase? | No, requires purchased tokens Token purchase required; $5 gets you 200K tokens | No, requires purchased tokens Token purchase required; $5 gets you 200K tokens |
| Model page on Rewind.ai | View GPT-5 → | View Grok 4 → |
GPT-5
Grok 4
Which one fits your work?
Spec tables narrow the field. For any real task, the most reliable test is: send the same prompt to both and compare the outputs yourself.
The Rewind.ai chat lets you switch models mid-conversation so you can run that test without switching tabs. The AI Arena also collects community votes on blind responses if you want a broader data point.
Try GPT-5 or Grok 4
Both models are premium external models. Each request draws from purchased tokens ($5 = 200K).
Start chattingFAQ
GPT-5 vs Grok 4 is a side-by-side comparison of two AI models. GPT-5 is built by OpenAI, and Grok 4 by xAI. Try each one at /chat/ on Rewind.ai and judge the answers yourself.
Not free, GPT-5 and Grok 4 are premium external models routed through third-party providers, so they require purchased tokens (starting at $5 for 200,000 tokens). Free-tier models are also available.
Depends on your workload. Try each one at /chat/ with your own prompts, benchmarks can only tell you so much. The model pages at /apps/openai-gpt-5/ and /apps/x-ai-grok-4/ list specs and pricing.
Yes, GPT-5 and Grok 4 are premium external models that need purchased tokens. You can create a free Rewind.ai account and buy tokens starting at $5 for 200K. Free-tier models work without an account.
Yes. The chat picker at /chat/ lets you switch between GPT-5, Grok 4, and any of 400+ other models at any time during a conversation.
Rewind.ai bills in tokens, not per-message. A typical chat turn on GPT-5 uses about 4,078 Rewind.ai tokens per message; on Grok 4, about 6,750 Rewind.ai tokens per message. $5 buys 200,000 tokens and they never expire. Free-tier models are free up to your daily allowance.
GPT-5 supports 400,000 tokens of context; Grok 4 supports 256,000 tokens. Context window is how much text the model can read in a single conversation before older messages start being trimmed.
Models on Rewind.ai are routed through OpenRouter to the underlying provider (OpenAI, xAI, or whichever you select). We don't store prompts or use them for training.
Yes. Both GPT-5 and Grok 4 are accessible through the Rewind.ai API, one Bearer token, OpenAI-compatible chat/completions. Paid models require purchased tokens (no API access from the daily free pool).
Check the individual model pages, /apps/openai-gpt-5/ and /apps/x-ai-grok-4/, for each model's specs. For your own workload, nothing beats sending the same prompts through /chat/.