GPT 5.5 vs Grok 4.5
What actually differs between GPT 5.5 and Grok 4.5 on Tokenator: context, output limit, image input, usage multiplier and current availability.
Specification table
Both models are served through the same OpenAI-compatible Tokenator endpoint — switching between them means changing the model field in your request. The table below lists only the attributes Tokenator takes from its own routing configuration, with no editorial guesswork.
| Attribute | GPT 5.5 | Grok 4.5 |
|---|---|---|
| API ID | gpt-5.5 | grok-4.5 |
| Model vendor | openai | x-ai |
| Type | Text model (chat / completions) | Text model (chat / completions) |
| Context window | 1.05M tokens | 500K tokens |
| Max output | 128K tokens | 128K tokens |
| Image input | yes | yes |
| Tokenator usage multiplier | 1.8× | 1.7× |
| API formats | /v1/chat/completions /v1/responses /v1/messages | /v1/chat/completions /v1/responses /v1/messages |
| Current status | available | available |
Quality on available benchmarks
Values come from the Artificial Analysis data loaded into the Tokenator catalog for these models. A dash means no data is loaded for that index.
| Metric | GPT 5.5 | Grok 4.5 |
|---|---|---|
| Intelligence index | 43.5 | 53.8 |
| Coding index | 60.9 | 72.4 |
| Agentic index | 30.4 | 45.7 |
Differences in purpose
GPT 5.5
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.
Grok 4.5
Grok 4.5 is SpaceXAI's smartest model with frontier performance on coding, knowledge work, and STEM.
Both IDs work in any tool that supports a custom base URL — see the integrations list.
Token usage
Tokenator deducts (input + output) × model multiplier from the key limit. GPT 5.5 has a multiplier of 1.8×, Grok 4.5 — 1.7×. A range means several upstream providers serve the model at different costs, so the final coefficient depends on which one handled the request.
See the API documentation for details on counting.
How to switch between the models
curl https://api.tokenator.top/v1/chat/completions \ -H "Authorization: Bearer sk-your-tokenator-key" \ -H "Content-Type: application/json" \ -d '{ "model": "gpt-5.5", "messages": [{"role": "user", "content": "Hello"}] }'
curl https://api.tokenator.top/v1/chat/completions \ -H "Authorization: Bearer sk-your-tokenator-key" \ -H "Content-Type: application/json" \ -d '{ "model": "grok-4.5", "messages": [{"role": "user", "content": "Hello"}] }'
FAQ
Does connecting GPT 5.5 differ from Grok 4.5?
No: same base URL, same key — only the model field changes.
Can one key use both models?
Yes, if both are in the key's allowed-model list. The list is visible in your account.
What happens if a model is unavailable?
Tokenator fails the request over to the next upstream provider for the same model by priority. With no active providers the request returns an error — current state is on the status page.