Compare / Models
GPT-5.5 vs Grok 4.5
Price, context window and capabilities side by side — read from the same catalog that meters your calls, not from a press release.
Grok 4.5 is 2.5x cheaper on input. Grok 4.5 is 5.0x cheaper on output. Grok 4.5 holds 500K tokens against 256K.
At a glance
Side by side
Specifications
Every difference we can measure
| GPT-5.5 | Grok 4.5 | |
|---|---|---|
| Input price | $5/M | $2/M |
| Output price | $30/M | $6/M |
| Context window | 256K tokens | 500K tokens |
| Vision | Yes | No |
| Tool calling | Yes | Yes |
| Long context | No | Yes |
A row appears only when we hold the fact for both models. Anything the provider has not published is left out rather than guessed, so an empty row is missing data and never a zero.
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FAQ
Frequently asked questions
What is the difference between GPT-5.5 and Grok 4.5?
Grok 4.5 is 2.5x cheaper on input. Grok 4.5 is 5.0x cheaper on output. Grok 4.5 holds 500K tokens against 256K. Only GPT-5.5 declares vision. Only Grok 4.5 declares long context. Both run on the same endpoint and the same key here, so trying each is a one-line change to the model id.
Which is cheaper, GPT-5.5 or Grok 4.5?
Grok 4.5 is, on input tokens. Output usually dominates the bill on generative work, so check the output row above against your own ratio of prompt to completion before deciding.
Can I switch between GPT-5.5 and Grok 4.5 without changing my code?
Yes. Both are OpenAI-compatible through one CompanyFabric key, so switching is the model string and nothing else — no second SDK, no second contract, one prepaid balance across both.
Do I have to choose?
No. Send companyfabric/auto and we route each request to the cheapest model that can serve it, which is how most people use both without deciding in advance.
One key. Every model. Exact prices.
Run GPT-5.5 and Grok 4.5 on the same key and compare them on your own prompts. Free starter credits included, no subscription required.